Programs 211-240


211-Smoking Moon

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Published PRX December 24 , 2015
Recorded December 15, 2015

Not long ago the only oceans of liquid salty water humans knew about were on planet Earth.

Recent data from spacecraft and ground based telescopes indicate that the Moon's of Jupiter,  Ganymede and Europa, as well as the asteroid Ceres are likely to have oceans of liquid water. 

Since 2005, the small, 313 mile diameter, icy moon of Saturn, Enceladus(N cel a dus),  has been observed to have icy plumes coming from cracks near its south polar regions.  When the NASA Cassini Spacecraft was programmed to fly through them, Cassini discovered that the material being ejected from Enceladus is composed of ice, water vapor and simple organic molecules.

In 2015, observations of a tiny wobble of Enceladus by the NASA Cassini mission were published in the scientific journal Icarus. "If the surface and core were rigidly connected, the core would provide so much dead weight the wobble would be far smaller than we observe it to be," said Dr. Matthew Tiscareno
(t ih s - k aa- r EH - n oh), a Cassini participating scientist at the SETI Institute and a co-author of the paper.  Dr. Tiscareno  continued "This proves that there must be a global layer of liquid separating the surface from the core". 

There are now 4 places in our solar system outside of mother Earth where salty water is in contact with warm rock layers.  We know that on Earth life abounds around hot water vents on the sea floor.  Could life exist under similar conditions on these other worlds?

For Travelers in the Night this is Dr. Al Grauer

Go to travelersinthenight.org program 211 for more information.

© 2015 A. D. Grauer and ℗ 2015 A. D. Grauer



212-Dead Comet

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Published PRX December 24 , 2015
Recorded December 15, 2015

A potentially hazardous asteroid made a close approach to our Moon and then to the Earth late in 2015.  2015 TB145 as it is now called, had come near humans six times between 1920 and 2015 but had gone unnoticed as it zipped through the night skies.  On the 2015 close approach to us, the Pan-STARRS group in Hawaii found it heading towards the Sun at a speed of 23 miles/second.  

On its 2015 close approach,  2015 TB145 was imaged by the RADAR at  Goldstone, the Green Bank Telescope,and the Arecibo Observatory.  These data show that this interesting object is about 2,000 feet in diameter and rotates about once every 5 hours.  Dr. Vishnu Reddy a research scientist at the Planetary Science Institute in Tucson, Arizona said "We found that the object reflects about six percent of the light it receives from the sun".  Dr. Reddy continued "That is similar to fresh asphalt, and while here on Earth we think that is pretty dark, it is brighter than a typical comet which reflects only 3 to 5 percent of the light.   Since 2015 TB145 reflects about half the light one would expect to obtain from a typical asteroid but we don't observe the gas cloud of an active comet we are led to the conclusion that 2015 TB145 is a dead comet. 

 What event gave 2015 TB145 a skull like appearance and placed on its current path remains a mystery. 

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 212 for more information.

© 2015 A. D. Grauer and ℗ 2015 A. D. Grauer

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213-Great Night

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Published PRX December 31 , 2015
Recorded December 15, 2015

On a long winter night my Catalina Sky Survey teammate Jess Johnson discovered a dozen new Earth approaching object candidates. In each case the object's motion was significantly different from that of the thousands of main belt asteroids he observed on the same night.   Followup observations from telescopes around the world allowed astronomers to find orbital paths and estimate the sizes of ten of Jess's discoveries.  The other two were lost and will have to be rediscovered in the future because clouds in the Earth's atmosphere limited the followup observations of them. 

Seven of Jess's new discoveries are Earth approaching objects which range in size from 30 to 387 feet in diameter.  None of them represent any threat to planet Earth.   

Two of them orbit the Sun along Earth like paths with a periods of about a year.  These objects may be candidates for human astronauts to visit in the future.

Three of Jess's discoveries with further observations turned out not to be Earth approaching asteroids.  One is a main belter, one is a Mars crosser, and the other is a Centaur.

The Centaur now called 2015 XY1 orbits the Sun every 33 years between the paths of Jupiter and Saturn on a path which is highly inclined to all of the planets and most of the asteroids.  It is perhaps 30 miles in diameter. In a few million years the pulls of the giant planets will cause its orbit to change and it is likely to become a comet.  Its fate is to collide with the Sun or a planet or perhaps to be ejected into interstellar space. 

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 213 for more information.

© 2015 A. D. Grauer and ℗ 2015 A. D. Grauer

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214-Jupiter's Comets


Published PRX December 31 , 2015 
Recorded December 15, 2015

The giant planet Jupiter has more than twice the mass of all of the other planets, asteroids, and comets in the solar system put together.  As well as its moons Jupiter's gravity controls the orbits of thousands of asteroids that proceed and trail it in its path around the Sun.  Jupiter also has a family of short period comets which it has collected from the Kuiper belt  beyond the orbit of the planet Neptune. The most well known of these, Comet Shoemaker-Levy met its fate in a collision with Jupiter more than 20 years ago.

A typical Jupiter family of comet's member orbits the Sun in less than 20 years. It actively produces a gas cloud or coma for perhaps a thousand orbits around the Sun over a period of time of 10,000 years or so. What is left after the volatile material evaporates is is a small dark rocky lump or rubble pile orbiting the Sun in an elliptical orbit. 

Recently my Catalina Sky Survey teammates Greg Leonard  and Rose Matheny were using a Schmidt telescope on Mt. Bigelow, AZ when they discovered an Earth approaching object now named 2015 XL128.  Observations from telescopes in Arizona, Pennsylvania, Germany, Italy, and France indicate that this new object is relatively large and on a 6 year path around the Sun. These data suggests that 2015 XL128 may be a dormant Jupiter Family Comet.   Not too worry, 2015 XL128 never gets closer than about 13.7 million miles from planet Earth.

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 214 for more information.

© 2015 A. D. Grauer and ℗ 2015 A. D. Grauer

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215-Blinky

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Published PRX January 7 , 2016
Recorded January 04, 2016

Some things immediately grab your attention. On a long winter's night my Catalina Sky Survey team Captain Eric Christensen was taking 4 images of the same place in the night sky spaced out over 45 minutes or so.  During this short interval nearby objects show up as a rapidly moving points of light.  Most of the time each of the images of the same object have about the same brightness.  To Eric's surprise on some of his images, his discovery was about  twice as bright as it was on others.    I nicknamed it "Blinky" and observed it the next night providing the additional data which allowed the Minor Planet Center to find its orbit and estimate its size.  These calculations provided some interesting surprises.  Turns out this object now named 2015 YJ had missed the Earth by 40,000 miles 59 hours earlier traveling at a speed of 10 miles per second. At that point it could have been spotted by a backyard telescope equipped with an electronic camera if anyone had been looking. Further, 6 hours and 29 minutes before it streaked by the Earth, 2015 YJ aka Blinky had missed the Moon by only 80,000 miles.

The fact that Blinky changes brightness rapidly suggests that it has an elongated shape and thus reflects different amounts of sunlight as it spins on its axis. 

If you had been on your way to the Moon in your space ship, seeing the tumbling 2015 YJ coming by at 10 miles/second would have gotten your adrenaline pumping. 

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 215 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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216-Blinky Revealed

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Published PRX January 7 , 2016
Recorded January 04, 2016

The Magdalena Ridge Observatory in New Mexico is home to the largest telescope in the world which is routinely used for Earth approaching asteroid research. The telescope's primary mirror is almost 8 feet in diameter and is housed in a mount which allows it to move around the sky at an amazing 10 degrees per second. Dr. Eileen Ryan is the observatory's director and her husband Dr. Bill Ryan uses this large telescope to study solar system objects.

On his discovery images, my Catalina Sky Survey team leader Eric Christensen was amazed to see rapid brightness changes in the Earth approaching asteroid he had just discovered. He immediately suspected it to be an irregularly shaped rapidly spinning object and contacted the Ryans for followup observations. I continued to track this object on my observing shift on the telescope and gave it the nickname "Blinky".  Dr. Bill Ryan's first observations of 2015 YJ aka Blinky encouraged him to continue to measure its brightness changes as it streaked through the night sky. In Dr. Bill Ryan's experiences a typical small Earth approaching object spins at a rate of once every two hours or so. When 2015 YJ tripled in brightness every 9 minutes he knew that Blinky is unusual and is spinning too fast for its tiny gravity to hold it together unless it is a solid object. 

Blinky is likely to be a collision fragment perhaps one and a half times longer that it is wide and is spinning on its axis once every 9 minutes. What violent event which created Blinky remains a mystery. 

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 216 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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217-How Close

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Published PRX January 14 , 2016
Recorded January 4, 2015

My team the Catalina Sky Survey takes four images of the same place in the sky spaced out over 45 minutes or so. A typical image contains tens of thousands of stars, scores of main belt asteroids, and perhaps a couple of Earth approaching asteroids. Our software picks out the moving objects, identifies those of the half a million or so that we know, and presents the unknown ones to the human at the telescope for further action.  Most of the potential Earth approaching asteroid candidates that the computer identifies are noise glitches, cosmic rays, or other types of electronic ghosts.  A few have a shape and motion which makes them appear to be real. After follow up observations later that night the observer at the telescope posts the observations on a public web page at the Minor Planet Center. Telescopes around the world track the new object until its path in the sky is determined.

Recently I used this process to discover an object now named 2015 YV1. When I first spotted it,  this 250 foot diameter space rock was 11.6 million miles from us and was moving away at almost 13 miles per second.   An object of this size enters the Earth's atmosphere every few thousand years producing an air burst equivalent to 16 million tons of TNT.  Not to worry, 2015 YV1's  2.5 year orbital path around our Sun will never bring it closer than about 1/4 the distance to the moon from the surface of planet Earth. 

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 217 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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218-Still Out There

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Published PRX January 14 , 2016
Recorded January 4, 2015

My Catalina Sky Survey team mate Carson Fuls has discovered an object which bears watching. At the beginning of a long winter's night of observing with a Schmidt telescope on Mt. Bigelow, Arizona,  Carson came across a fast moving point of light in the night sky.  He checked to make sure that it is a real object by observing it again a few hours later.   After posting his observations on a public website at the IAU Minor Planet Center this new Earth approaching asteroid candidate was tracked by telescopes in Arizona, Japan, Italy, France, Texas, Hungary, and the Czech Republic. These data enabled the scientists at the Minor Planet Center to identify it as a potentially hazardous asteroid, calculate its orbit around the Sun, estimate its size, and give it the name 2015 YY9.

Carson's new space rock, 2015 YY9 is about 480 feet in diameter, orbits the Sun once every two and a half years, and can make close approaches to Venus, Earth, our Moon, and Mars. 

Fortunately 2015 YY9's current orbit never allows it to come closer than about 3/4 the Moon's distance from us.  An asteroid of this size strikes the Earth every 16,000 years or so producing an air burst three times greater than the largest hydrogen bomb ever exploded and a crater a mile and a half in diameter.

Carson's discovery alerts asteroid hunters to the fact that large dangerous unknown asteroids are still out there.  

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 218 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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219-Zero

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Published PRX January 21 , 2016
Recorded January 13, 2016

I had to look at my computer screen a second time to be sure. What I saw is that a newly discovered object's path had a zero distance between it and the Earth's orbit around the Sun. When asteroid hunters find and track a new Earth approaching asteroid we determine how close its orbit comes to that of planet Earth.  We call that measurement its Earth Minimum Orbit Intersection Distance. Its units are the AU which is the Earth's distance from the Sun.  In these units the Moon is .0027AU from us.  Recently my Catalina Sky Survey team Captain Eric Christensen discovered a small space rock with a minimum orbital intersection distance of 0.0000 AU.  This does not mean it will hit the Earth anytime soon because it an the Earth would have to both be there for that to happen.  However, this space rock has gotten asteroid hunter's  attention since we seldom see an object whose path so nearly crosses ours.

This new objects name is 2016 AM2.   It is about the same size as the one which entered the Earth's atmosphere over Russia in 2013 injuring nearly 1,500 people.  In 2015 this small space rock missed both the Earth and our moon by several hundred thousand miles.

2016 AM2's current path comes less than an Earth radius from our planet's path about the Sun.  So far we have observed this space rock for only 2 days out of its 958 day path around the Sun. We will need obtain more data on 2016 AM2 the next time it comes near to be able to determine if and/or when a collision might occur.

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 219 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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220-Deuce

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Published PRX January 21 , 2016
Recorded January 13, 2016

A picture of your teeth in visible light shows what is on the outside while one taken in X-rays reveals what is inside.  In a similar way images of comets in visible light show what is on the outside while those obtained using their thermal infrared glow tell you about their innards.

The NASA/NEOWISE mission utilizes a spacecraft whose orbit passes above the North and South poles.  Its infrared eyes point opposite to the Earth at a right angle to direction of the Sun.  Comets discovered by NEOWISE are detected by measuring their thermal infrared glow.  NEOWISE can thus find comets which are dark and do not reflect much sunlight in the visible part of the spectrum.

Within the space of 31 hours the NASA/NEOWISE spacecraft reported the discovery of a pair of comets. 

One of them, C/2015 X8 has an orbital period of about 121 years.  It is currently heading away from the Sun on a path that will take it to between the orbits of Uranus and Neptune before it heads back in our direction again.

The other, C/2015 YG1 has a period of 350 years or so and is on a path which does not come as close to the Sun as the planet Mars.  It travels a very elliptical path which extends to well beyond the dwarf planet Pluto. 

It is likely that the gravity of the giant planet Jupiter will change the orbits of these two comets.  It could direct them towards the Earth, the Sun, or fling them from the solar system.

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 220 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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221-Human Geological Epoch

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Published PRX January 28 , 2016
Recorded January 13, 2016

In the space of less than a human lifetime most of the people on Earth no longer are able to experience the wonders of the natural night sky.

If your are wondering how far the human race has gone in changing our planet, you should consider the work of researchers who are members of the Geological Society of London.  This group of scientists have published a paper in the Journal GSA Today in which they present hard evidence that human activity has caused changes in erosion and sediment build up worldwide, produced changes in the the carbon cycle and the global temperature, precipitated profound changes in the plant and animal kingdoms, and has changed the acidity of the worlds oceans.

Dr Colin Waters of the British Geological Survey said: "Humans have long affected the environment, but recently there has been a rapid global spread of novel materials including aluminium, concrete and plastics, which are leaving their mark in sediments. Fossil-fuel combustion has dispersed fly ash particles worldwide, pretty well coincident with the peak distribution of the 'bomb spike' of radionuclides generated by atmospheric testing of nuclear weapons."

Human activity is thus being written into rock and ice layers currently being produced on planet Earth and suggests that we are embarking on a new geological epoch which may be named the Anthropocene.

It is time for our race to change some of its ways or be prepared to face the consequences of a radically different planetary environment.

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 221 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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222-A Haul


Published PRX January 28 , 2016
Recorded January 13, 2016

My team, the Catalina Sky Survey, discovered a very diverse group of 566 Earth approaching objects in 2015.  Fortunately none of them will strike the Earth anytime soon. The smallest has a diameter which is less than the height of an NBA basketball player while the largest is nearly a mile in diameter.  Most of these space rocks are small.  424 have diameters which would allow them to fit between the goal posts of a NFL football field.  None of the 119 large enough to cause serious damage to humans are on a collision course with planet Earth.

These 566 Earth Approaching asteroids orbit the Sun with periods from less than a year to three plus years in length.  All of their orbits can bring them near to the path of planet Earth about the Sun.  Sixty four of these space rocks can come closer to us than the Moon.  One of them, 2015 AQ43 is about 30 feet in diameter and missed us by less than an Earth diameter in 2010 without being noticed. Three of them were relatively near misses in that they came less than the Earth's circumference from us in 2015.

My team, the NASA Sponsored Catalina Sky Survey continues to be on the look out for space rocks 24 nights every month using two telescopes in the Catalina Mountains north of Tucson, Arizona. Our goal is to find any large objects at least 50 years before they get too close for comfort to planet Earth.

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 222 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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223-Back Home

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Published PRX February 4 , 2016
Recorded January 31, 2016

When my Catalina Sky Survey teammate Rose Matheny started tracking a rapidly moving point of light in the night sky she had no idea that it would collide with planet Earth 41 days later.   Rose's observations along with data taken by telescopes around the world were used to calculate the mystery object's path through space.  These new data along with observations made in previous years of an object which had been tracked and lost several times were used to predict an impact over the ocean south of Sri Lanka.  The fireball occurred right on schedule. 

We now have some clues about the properties of Rose's object WT1190F.  From its orbit it must have had a density of about a tenth that of water.   The United Arab Emirates Space agency chartered a plane which enabled the scientists aboard to photograph WT1190F as it broke up and burned at high altitude.  The spectrum obtained by these researchers indicated the presence of titanium oxide and hydrogen.  These clues are consistent with what would be expected if WT1190F had been a spent rocket casing.

The question then became, "which rocket?".  It is unlikely that a discarded piece from an Apollo mission could have survived in WT1190F's orbit for 40 plus years without colliding with the Earth or going into orbit around the Sun.   Speculation is that WT1190F was a spent rocket which had been used to propel the NASA Prospector Satellite to the Moon in 1998.

In any event WT1190F enters the history books as the third object which was detected in outer space before entering the Earth's atmosphere.

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 223 for more information. 

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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224-Aten Ahead

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Published PRX February 4 , 2016
Recorded January 31, 2016

Asteroids travel in elliptical orbits  about the Sun .  About 6% of the Earth approaching asteroids we discover have an orbit which causes them to spend much of their time closer to the Sun than our home planet.  They are called Atens.  About one hundred of them are large enough and can come close enough to be considered potentially hazardous to humans.

Recently my Catalina Sky Survey teammate Carson Fuls discovered a 470 foot diameter, potentially hazardous Aten asteroid, now called 2016 AK193.  It orbits the Sun once every 296 days on a path that takes it from inside the orbit of Venus out to 10% further from the Sun than the planet Earth.  When Carson first spotted 2016 AK193 it was ten million miles from him traveling towards the Earth at 6.6 miles per second. Subsequently it was tracked by telescopes at 14 observatories around the world as it made its approach to planet Earth.  Turns out that this large space rock had visited the Earth's neighborhood in 1917 and 1930 not to return again until 2016.  It will not come this close again until 2115.  

Fortunately Carson's discovery does not come closer to us than about 15 times the distance to our moon.  One its size strikes the Earth every 16,000 years or so making a crater a mile and a half in diameter.

Aten asteroids spend most of their time inside the Earth's orbit, come close to us, travel at speeds our rockets can match,  and may be an economical source of raw materials for space exploration. 

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 224 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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225-Greg Scores

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Published PRX February 11 , 2016
Recorded January 31, 2016

The Congress of the United States has directed NASA to find and catalog asteroids which pose a possible threat to planet Earth.  My team the Catalina Sky Survey is part of that effort.  Particular attention is paid to objects which are large enough and come close enough to bear watching.  Asteroid hunters have discovered nearly 1,700 of these potentially hazardous asteroids.  Recently my newest teammate Greg Leonard discovered one to add to the list.  When Greg became the first human to spot 2016 BE1 it was 24 million miles from planet Earth and was moving away from him at 4.3 miles per second.  About 5 weeks earlier when it was nearest to us it was too dim to be seen as it approached the Earth from the direction of the Sun.  During its 2016 close approach 2016 BE1 was bright enough to be detected for about 4 months out of its 40 month trip around the Sun.

Greg's new space rock is nearly a thousand feet in diameter.  One its size strikes the Earth every 75,000 years or so creating a crater 3 miles in diameter and devastation over a hurricane sized foot print on our planet. Fortunately Greg's new object never comes closer than about twelve and a half times the Moon's distance from us.
There are likely to be 10,000 or more Earth approaching asteroids the size of 2016 BE1.  

Since asteroid hunter's main concern are the large space rocks which we don't know about, my team the Catalina Sky Survey continues to scan the skies 24 nights per month using two telescopes located in the Catalina Mountains near Tucson, Arizona.

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 225 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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226-Cosmic Campground

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Published PRX February 11 , 2016
Recorded February 1, 2016

On a mesa within the Gila National Forest the Cosmic Campground is in one of the last areas of natural night sky in the lower 48.  It's location between the Gila Wilderness and the Blue Range Primitive Area in southwestern New Mexico features a 360 degree view of the night sky at elevation of 5,300 feet above sea level.  The climate at the site is dry with many clear nights.  These attributes and the absence of artificial light pollution has prompted the International Dark Sky Association to designate the Cosmic Campground as an International Dark Sky Sanctuary.  The only other site in the world so designated is the Cerro Tololo Inter-American Observatory in Chile which is the home of a world class astronomical research complex.

Ann Grauer of the Friends of the Cosmic Campground sums up well the motivation for seeking the International Dark Sky Association designation “We are honored to help preserve and protect this small, dark place for present and future generations to connect with their inherent fascination and attraction to our night sky.”

At the Cosmic Campground your dark adapted eyes, binoculars, and/or a telescope will put you in direct personal contact with the wonders of a natural night sky.  One of the most spectacular sights I have been fortunate to experience is the Milky Way rising over the Gila wilderness at the Cosmic Campground.  Visit the Cosmic Campground to see the Milky Way, star clusters, faint galaxies, the zodiacal light, and many other wonders of the natural night sky for yourself.

For Travelers in the Night this is Dr. Al Grauer.

Go to cosmiccampground.org and travelersinthenight.org program 226 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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227-Planet 9

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Published PRX February 18 , 2016
Recorded February 1, 2016

From the dawn of history, the planets Mercury, Venus, Mars, Jupiter and Saturn have been part of human culture. The planet Uranus had been mistaken for a dim star until Sir William Herschel trained his telescope on it in 1781.  When astronomers began to observe Uranus they realized that it is a planet and that it's orbit suggested the presence of an unknown planet further from the Sun.   When astronomers looked for it there it was.  The new planet was named Neptune.  Fifty years later Percival Lowell maintained that variations in the orbit of Neptune suggested the existence of yet another planet which he named Planet X.  Clyde Tombaugh carried out the search for Planet X after Lowell died and in 1930 discovered a distant planetary object.  It was named Pluto and reigned as the ninth planet for the next 65 years.  By 2005 a number of other Pluto like objects had been found in orbits far from the Sun.  None of these were large enough to have cleared the neighborhood around them like the other 8 planets.  Pluto and the rest of the new objects were then designated as dwarf planets. 

Now astronomers are doing it again.  Calculations based on the orbits of  the distant objects out near Pluto suggest the existence of a 10 Earth mass planet twenty times farther from the Sun than the planet Neptune.  At its great distance the hypothetical new "Planet 9" would take 20,000 years or so to make a single orbit about the Sun.  The search for "Planet 9" has begun. Until we have images of it moving through the night sky it will continue to be a theoretical curiosity. 

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 227 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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228-Alien Contact

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Published PRX February 18 , 2016
Recorded February 4, 2016

You could wake up any morning to the news that humans have found life beyond our planet.  It could be fossils of ancient life on Mars. It could be the discovery of micro organisms in one of the salty oceans on the asteroid Ceres, the moons of Jupiter, Europa and Ganymede, and/or Enceladus the strange little moon of Saturn.  It could be the reception of electromagnetic signals from a distant advanced civilization. 

The effect of such a discovery on humanity would depend on the type of alien life discovered and its distance from us.  Some have wondered if humanity might be end up second best in a physical interaction with an alien culture as was the case of the Aztecs at the hands of Cortez and his fellow invaders.  Others have wondered if information gleaned from alien radio signals would be used for good or evil by the residents of our planet.  These arguments have been used to suggest that we avoid communiting with off world civilizations.

Even the discovery of lowly microorganisms outside of our biosphere has great promise and risks.

To prepare for these possibilities scientists are studying life at extreme ocean depths, temperatures, and pressures as well as in the high dry cold desert regions of Antarctica to see how life as we know it has adapted  to extreme conditions.  Other researchers scan the skies searching for alien signals from distant sources.  Additional groups of scientists are planning space missions to continue to search for life in our own solar system.

Lacking hard evidence many of us continue to look into the night sky and wonder what is out there.

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 228 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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229-Close Duo

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Published PRX February 25 , 2016
Recorded February 16, 2016

On consecutive nights my Catalina Sky Survey teammate Richard Kowalski discovered two very close approaching asteroids.

The first 2016 BA15, orbits the Sun once every 1.91 years. It can come to an Earth's diameter from the surface of our planet. This 50 foot diameter space rock makes many relatively close visits to the Earth, our Moon, Venus, and Mars.  It is not a current threat to our planet.

The second of Kowalski's close approaching asteroids is 2016 BY14. 84 days before Richard spotted it, this tough space rock streaked by the Earth at 35 miles per second on its way to the Sun.  Forty days later it was 65% of the planet Mercury's distance from the Sun and was traveling at an amazing 51 miles per second.   After rounding the Sun, 2016 BY14 headed for a close approach to Planet Earth.  Six days after it was closest and brightest as seen from Earth, Richard spotted this asteroid 11 million miles away from him traveling towards the orbit of Jupiter at 20 miles per second.

Richard's discovery, 2016 BY14 must be made out of pretty tough stuff since when it was closest to the Sun it received more than twice the solar energy which heats the surface of Mercury to 800 F.    Asteroid hunter's continue to need to track 2016 BY14 to make sure that its orbit does not change to make it a threat as it passes near the paths of Mercury, Venus, Earth, our Moon, Mars, and Jupiter. 

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 229 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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230-Close Or Not


Published PRX February 25 , 2016
Recorded February 16, 2016

In 2013 my Catalina Sky Survey teammate Steve Larson discovered a space rock streaking through the night sky. For the next 3 days this object was observed by telescopes in California, England, Chile, and New Mexico and given the name 2013 TX68.  About 10 days after being discovered, this small asteroid became invisible to human telescopes as it moved towards the Sun with increasing amounts of its dark side facing towards us.  After more than 2 years 2013 TX68 is predicted to once again become bright enough for Earth's telescopes to detect. However, since we have followed this asteroid for only 3 days out of its 780 day orbit around the Sun its trajectory is ill defined.  According to NASA scientists at the Jet Propulsion Laboratory, in early March of 2016, Steve Larson's 100 foot diameter space rock, will pass somewhere between 11,000  and 9 million miles of planet Earth. 

If 2013 TX68 follows the most likely of its many possible paths it will be a most interesting sight as it passes a bit farther than the Moon from us.  It will brighten by more than 250 times in less than a day.  For a celestial object it will be moving very fast.  Its maximum apparent motion will be about the diameter of the Moon every 5 minutes.

Hopefully asteroid hunters will come across 2013 TX68 during its 2016 encounter with Earth.  The data obtained will allow us to predict when and how close it will approach our to home planet in future years.

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 230 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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231-Hot Hand

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Published PRX March 3 , 2016
Recorded February 16, 2016

Every year asteroid hunters discover about a hundred objects which are larger than 450 feet in diameter and come closer than 20 times the Moon's distance from us.  We call these potentially hazardous asteroids.  In 2015 my group the Catalina Sky Survey discovered 21 of them.  It was thus exiciting news to our team, when, recently, our newest team member Greg Leonard discovered three of them in rapid succession.

Two of Greg's discoveries are a thousand feet in diameter while the third is approximately 1,800 feet in diameter.  Fortunately none of them are on a collision course with planet Earth. The Congress of the United States has directed NASA to discover large, potentially dangerous asteroids like these since if one should impact the Earth it would release several times the energy of the largest hydrogen bomb ever exploded.  Asteroid hunters's goal is to prevent such a disaster by discovering an Earth bound asteroid at least 50 years before it hits.   Serious engineering studies are being conducted to determine the best way to deflect an asteroid which appears to be on a collision course with Earth.  One proposal involves changing the path of a threatening asteroid by striking it with a high velocity impacting space craft.   Another involves using a "gravity tractor" to exert a tiny force for a long time causing the asteroid to miss the Earth.  A third involves setting off a nuclear blast adjacent to the asteroid to  vaporize a portion of its surface.  This will produce a rocket type of thrust to change the threatening object's trajectory.

The goal of the NASA Near Earth Object program is to provide the early detection critical to any of these mitigation techniques.

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 231 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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232-Dangerous Aten


Published PRX March 3 , 2016
Recorded February 16, 2016

About one in twenty Earth approaching objects that asteroid hunters discover has a path which is mostly inside of the Earth's orbit around the Sun. We call them Atens. They are hard to discover since they spend much of their time shrouded by solar glare. A large percentage of Aten asteroids are economically attractive. Some of them are likely to contain nickel, cobalt, gold, and platinum.

Recently my Catalina Sky Survey teammate Rose Matheny discovered a potentially hazardous Aten asteroid now called 2016 CL136.  Rose was able to discover this object when it emerged from the solar glare traveling at 12 miles per second.  Humans were able to observe Rose's space rock for another month until it became too faint to detect. 2016 CL136 orbits the Sun every 227 days on a path that takes it from inside the orbit of the planet Mercury to 18% farther from the the Sun than the planet Earth.  It must be made out of tough rocky metallic stuff, since when it is closest to the Sun its surface temperature is likely to be above 800F and it is traveling 45 miles per second relative to our star.  Rose's 580 foot diameter discovery will make 16 close approaches to planet Earth in the next 50 years with the closest being in 2021 when it will be about 13 times the Moon's distance from humans.  

Like the rest of the more than 1,700 known potentially hazardous asteroids, asteroid hunters will continue to track 2016 CL136. 

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 232 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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233-Tiny Visitor

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Published PRX March 10, 2016
Recorded February 28, 2016

An SUV sized space rock has spent eons traveling through the silent vacuum of space.  In the past 50 years, without humans being aware of its existence,  it has made 29 close approaches to planet Earth and 11 visits to the vicinity our sister planet Venus.  In 2016 as it approached the Earth from the direction of the Sun this small asteroid got about 100 times brighter in 8 hours.  Twenty three hours before my Catalina Sky Survey teammate Carson Fuls discovered this small space rock, it was about 3 times the Earth's circumference from us. After Carson discovered it streaking through the night sky at 5.7 miles per second, this tiny asteroid was observed by telescopes in Arizona, France, New Mexico, and Pennsylvania and given the name 2016 DB.

There are likely to be more than 100 million asteroids the size of Carson's discovery which make close approaches to us.  One the size of 2016 DB enters the Earth's atmosphere every 3 or 4 years, explodes 24 miles above our planet's surface, and releases the energy of a small nuclear weapon.  Currently the infrasound detectors designed to listen for nuclear explosions are able to detect and locate the point of impact of small space rocks.  So far we have been able to detect only two of these impactors before they entered the Earth's atmosphere.  In the relatively near future asteroid hunters will be able to find more of them before impact and thus be able to issue a warning for a space rock which is about to explode over a populated area.  

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 233 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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234-Salty and Cold


Published PRX March 10 , 2016
Recorded February 28, 2016

There is increasing evidence that Jupiter's moon Europa, Saturn's moon Enceladus, and other bodies in our solar system have oceans of salty liquid water in contact with warm rock layers.  We know that on Earth life abounds under these conditions around volcanic vents. Could such biodiversity be happening elsewhere?

Caltech's Dr. Mike Brown and JPL's Dr. Kevin Hand  have used the giant Keck telescope on the island of Hawaii to obtain evidence that the surface of Europa contains chemicals from it's subsurface ocean.  These findings suggest that energy from Europa's interior is warming its 60 mile deep ocean to the point that some material is being extruded from cracks and then deposited on it's surface.  These data have led Brown and Hand to hypothesize that the subsurface ocean on Europa contains sodium and potassium chlorides and may be very similar to the oceans here on planet Earth.

The fractured icy terrain on Europa containing sulfur and iron has led planetary scientists to similar analog sites on planet Earth.  One of these is Blood Falls on the Taylor glacier in Antarctica where an iron rich spring creates a blood red frozen waterfall at the edge of the ice sheet.  The other is Borup Fiord Pass on Ellesmere Island in the Canadian arctic.  The sulfur-oxidizing and sulfur-metabolizing bacteria found there produce a bio-signature, which if present on Europa, could be read by an orbiting spacecraft.  We need to get with it since climate change could eliminate these Earthly research sites in the next 20 years.

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 234 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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235-Fragment

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Published PRX March 17, 2016
Recorded February 28, 2016

Millions of years ago two large asteroids collided in the asteroid belt.  Pieces were sent flying in all directions.  A few of them were put into orbits which rise high above and below the plane of the solar system as they continued to travel around the Sun.  

Recently my Catalina Sky Survey teammate Richard Kowalski discovered one such a fragment.   He was observing with a 60 inch telescope on Mt. Lemmon in Arizona when a fast unknown moving point of light appeared on a set of his images.  Over the next six nights this new object was tracked by telescopes in Arizona and Texas.
Scientists at the Minor Planet Center used these data to determine it's orbit, estimate it's size, and give it the name 2016 DP.

Richard's new Earth approaching asteroid, 2016 DP, is about a quarter of a mile in diameter, orbits the Sun once every 377 days, and can come to about 13 times the Moon's distance from us.  It is categorized as a Potentially Hazardous Asteroid which means that asteroid hunters will need to keep special track of it.  In 1943 Richard's large space rock came much closer to Earth than it did in 2016 when he discovered it.  In 2062,  2016 DP,  will come much closer to our sister planet Venus than it ever does to Earth.  

Fortunately 2016 DP will not strike the Earth anytime soon.  It will continue to orbit the Sun in the silent vacuum of space until it has a collision with another asteroid or comet in the far distant future.

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 235 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

236-Enceladus's Ocean


Published PRX March 17 , 2016
Recorded February 28, 2016

Pound for pound Saturn's moon Enceladus is the brightest object in our solar system.  It is so shiny that it reflects most of the sunlight that strikes it.  Since Enceladus absorbs little sunlight it's surface is 330 degrees below zero Fahrenheit.  Below its icy exterior the story is very different.

For almost two hundred years since William Hershel discovered Enceladus, little was known about this point of light orbiting the distant planet Saturn.  The situation changed when the NASA Cassini spacecraft began to take pictures as it orbited the ringed planet.  Scientists were amazed when Cassini images showed plumes of gas being ejected into space from Enceladus.  In the past ten years a number of spacecraft flybys have been used to uncover evidence that it is likely that this icy moon has a layer of liquid water beneath its surface.

We know that on Earth life abounds near volcanic vents on the ocean floor.  Could such a situation exist on Enceladus?  This is a tough question to answer about an object whose diameter is about the width of the State of Arizona and never gets closer than about 3/4 of a billion miles from us.   Recently Dr. Christopher Glein and his team of researchers used Cassini spacecraft observations to find some interesting clues about Enceladus's oceans.  Their data suggests that what is happening on this tiny moon of Saturn is similar to what we find near the low temperature hydrothermal vent field called the lost field in the Atlantic Ocean.  What next.

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 236 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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237-Lost

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Published PRX March 24, 2016
Recorded March 24, 2016

In 1916 the 60 inch Hale telescope on Mt. Wilson, California was the largest telescope in the world.
Seth Nicholson and Harlow Shapley used it to discover a 2 mile wide asteroid.  They only observed their new asteroid twice on their discovery night.  Shapley named the asteroid Mildred for his one year old daughter.  Nicholson and Shapley were able to find asteroid Mildred a couple of times during the month after it's discovery. After that it's 1324 day orbit around the Sun was so poorly defined that astronomers did not know where to point their telescopes to observe it and Mildred was declared "lost".

Friends of Mildred Shapley Matthews would always ask her if she was found yet. In fact it was not until she was 76 years old that Dr. Gareth Williams rediscovered "lost" asteroid Mildred.   After 3/4 of a century of being lost, Mildred was found.

During her nearly 101 years of life Mildred Shapley Matthews had many distinctions in addition to having been lost in the solar system for 75 years. Starting when most people retire she began her second career as co-editor of the the Space Science Series at the University of Arizona. She was widely known as a tough, polite, and fair editor. The more than 20 volumes which she edited ignited countless individuals to embark on careers as planetary scientists.  Mildred Shapley Matthews retired again at 81 and traveled extensively until she was 99.  She passed away 4 days before her 101st birthday leaving us with memories of a life well lived.

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 237 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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238-Now Three

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Published PRX March 24 , 2016
Recorded March 24, 2016

The Catalina Sky Survey began with the University of Arizona's 30 inch Schmidt Telescope on Mt. Bigelow. This telescope became the world leader when it was used to discover 148 Earth approaching objects in 2005. It found the most Potentially Hazardous Asteroids for the next three years running. In 2006 the University of Arizona's 60 inch telescope on nearby Mt. Lemmon received a new camera and many upgrades. In spite of the fact that this telescope was old enough for senior citizen discounts it rapidly became the world's leader in the discovery of Earth approaching asteroids. These telescopes began to make so many discoveries that a telescope which could observe newly discovered objects long enough so that their orbits around the Sun could be nailed down became a necessity. To fill this need an old unused 40 inch telescope was overhauled and installed in a new dome next to the 60 inch telescope on Mt. Lemmon.  

The plan for the refurbished 40 inch was make it a robot with software designed specifically to track newly discovered Earth approaching asteroids. As might be expected such a software system is easier to think about that it is to implement. Alex Gibbs who is the Catalina Sky Survey's principal engineer took on this herculean task.
The result is a followup telescope which really works well. This has relieved the 60 inch of followup duties which is allowing it to spend more time searching the skies for new objects.

The Catalina Sky Survey now operates three telescopes, 24 nights per month, in the Catalina mountains north of Tucson, Arizona. 

For Travelers in the Night this is Dr. Al Grauer

Go to travelersinthenight.org program 238 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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239-Martian Lakes

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Published PRX April 4, 2016
Recorded April 3, 2016

It is likely that the first humans on Earth were aware of and had names for what we now call the planet Mars.  They knew it as a light in the night sky which radically changed in position and brightness relative to the stars.  When the telescope was invented observers on Earth saw Mars to be a small world similar to our own. When the first space craft photographed Mars close up it looked like our Moon and not very Earth like.  The human view of Mars changed radically again when orbiters started sending back detailed images and robotic probes began to land on the red planet. Turns out that Mars has surface conditions somewhere between the Earth and our Moon.  It appears that in the past the red planet was much more Earth like than it is now.

Recently Dr. Alexis Rodriguez of the Planetary Science Institute in Tucson, Arizona and his coauthors have published a paper in which they suggest that shallow lakes could have formed on Mars in the past few tens of millions years in a way similar to what occurs on the Tibetan plateau here on Earth.  Dr. Rodriguez plans to followup this paper with an expedition to Tibet to explore land forms which appear very similar to what we observe on Mars.  In particular he plans to visit the sediment ridges seen at the edges of Tibetan lakes since they are strikingly similar to what can be seen on high resolution images of the shore lines of ancient Martian lake beds.

The ancient lake sites which Dr. Rodriguez and his colleagues are studying on Mars are places were warm liquid ground water is likely to have been discharged for billions of years.     These areas on the red planet have the right temperatures, liquid water, and nutrients to support life as we know it. They may be the best places to look for evidence for life on our neighbor Mars.

For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 239 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

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240-Why

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Published PRX April 4, 2016
Recorded April 3, 2016

Recently my Catalina Sky Survey teammate Jess Johnson answered the question "Why do asteroid hunters go to the telescope?".  Jess was observing with the University of Arizona's Schmidt telescope on Mt. Bigelow when a fast moving streak of light showed up in a set of his images.  Over the next two days Jess's new object was observed by telescopes in  Arizona, New Mexico, England, France, Kansas, and Texas.  The Minor Planet Center used these data to give it the name 2016 EE156, calculate its size, and plot it's orbit around the Sun. Turns out that this object is exactly the type of dangerous asteroid that the United States Congress directed NASA to search for.  One the size of 2016 EE156 impacts Earth every 440,000 years or so releasing  the energy of 46,000 million tons of TNT producing a crater 8.5 miles in diameter.  Such an event is likely to create global climate change on our home planet.  

Fortunately, Jess's object, 2016 EE156 will not strike Earth in the foreseeable future.

We now know about approximately 900 close approaching asteroids like 2016 EE156 and suspect that there are at least 100 more out there for us to find.  It is these large ones that continue to motivate my Catalina Sky Survey team members to use our three telescopes 24 nights per month to search for objects that could pose a threat to humanity.

For Travelers in the Night this is Dr. Al Grauer. 

Go to travelersinthenight.org program 240 for more information.

© 2016 A. D. Grauer and ℗ 2016 A. D. Grauer

















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