Programs 121-150

Travelers in The Night



121- Three Is A Mystery

Click to Listen

Published PRX February 12 , 2015
Recorded February 02, 2015

Joe Leaphorn, Tony Hillerman's famous Navajo Police Detective was fond of stating his belief that there is no such thing as a coincidence. Is the same point of view valid when one is confronted with an asteroid hunting mystery?

Within a time span of one and a half hours, the two telescopes of the NASA funded, University of Arizona, Catalina Sky Survey, discovered three asteroids whose orbits are similar enough to grab one's attention.  However, they different enough to keep us from jumping to the conclusion that they are part of an asteroid collision fragment family.

The three Earth approaching asteroids in question are all about 30 feet in diameter and have similar eccentric orbits around the Sun. On the other hand their orbital periods around the Sun differ by more than 100 days which means that unless they broke up fairly recently they would not still be together.  There is no evidence for such a fragment producing breakup.

There are more than 30 families of asteroids in the main belt between Mars and Jupiter.  These groups have apparently been produced by collisions.  The Sloan Digital Survey in New Mexico has measured the positions brightnesses, and colors of more than 100,000 asteroids which have been used to make a beautiful movie. It is called "Painted Stone" and was created by Dr. Alex Parker of the Tucson, Arizona based Southwest Research Institute. Check it out and see asteroid families for yourself.

There has been some speculation about the possibility of killer asteroid swarms which threaten the Earth.  There is no evidence to support these ideas. 

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

Go to travelersinthenight.org program 121 for more information.

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


More Information On This Program

122-This Comet Will Never Return

Click to Listen

Published PRX February 12 , 2015
Recorded February 02, 2015

Unlike Halley's [h AE - l ee ] comet which returns to our neighborhood once about every 76 years,  Comet C2013 US10/Catalina will pass this way once never to return.

This strange object was discovered by my Catalina Sky Survey teammate, Richard Kowalski in 2013.  He discovered it as a faint, tiny, moving point of light in the night sky when it was 930 million miles away from planet Earth and was traveling at 16 miles per second in our direction.

All during 2014 and most of 2015,  Comet C2013 US10/Catalina accelerated under the relentless pull of the Sun's gravity. On October 16, 2015 it will cross the Earth's orbit, 16 million miles from us, and may be bright enough to see in a small telescope or binoculars. A month later it will be at its closest point to the Sun and be traveling 29 miles per second relative to it. By mid December of 2015 Kowalski's comet will be moving away from the Sun and be visible to us. Seiichi Yoshida has predicted its brightness and has charts on where to look for it in the night sky on his www.aerith.net,  website.  In 2028 Kowalski's comet will pass Pluto's average distance from the Sun. After that it will continue to move away from the Sun, become an interstellar traveler in the night, and perhaps some day a countless number of human lifetimes from now become a comet in another solar system. 

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

Go to travelersinthenight.org program 122 for more information.

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


More Information On This Program

123-A New Discovery Not

Click to Listen

Published PRX February 19 , 2015
Recorded February 06, 2015

I was observing with the NASA funded, Catalina Sky Survey, 60 inch telescope on Mt. Lemmon, when I found an interesting moving point of light in the night sky. It appeared to be on the path of an Earth approaching asteroid.  I submitted my observations to the Minor Planet Center.  Telescopes in Germany, New Mexico, Illinois, Pennsylvania, and England observed it.  The Minor Planet Center used these data to calculate an orbit.  This orbit revealed the asteroid to be large enough and close enough to classify it as a Potentially Hazardous Asteroid.  It was given the name 2015 BY310.  

A few days later the Minor Planet Center connected the observations of the object that they had been calling 2015 BY310 with an asteroid 2000 BK19. It had been discovered 15 years previously by the Lincoln Near-Earth Asteroid Research Program in New Mexico.  These new data confirm that it is is an Earth approaching asteroid but that it is slightly smaller than is required to give it the potentially hazardous label.

Now we know that 2000 BK19 alias  2015 BY310 is about the size of a football field.  It orbits the Sun every 3.7 years on a path that goes from near our home planet halfway out to the planet Jupiter.  In the extremely unlikely event that this small asteroid ever did enter the Earth's atmosphere it would release the energy of one hundred million tons of TNT.  The asteroid hunting community will continue to observe it to make sure that its orbit does not change, to make it a threat, as it passes other objects in space.

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

Go to travelersinthenight.org program 123 for more information.

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


More Information On This Program

124-Great Shefford Observatory

Click to Listen

Published PRX February 19 , 2015
Recorded February 06, 2015

Six inches from the kickers foot, it is hard to guess if it will be a goal in soccer or a field goal in American football.  You need to see the arc of the ball to make an accurate judgement.  The same is true in asteroid hunting.

On the first night an Earth approaching asteroid candidate is discovered, one is lucky to obtain observations for a few hours along its path in the sky.  Since a typical near Earth asteroid takes from a few hundred days to several years to complete a trip around the Sun, it takes more than a few hours of data to be able to predict where it will go. 

Peter Birtwhistle of the Great Shefford Observatory in England is one of unsung heroes of the asteroid hunting community.  On a recent observing run he helped to determine the orbits of several objects which I discovered with the NASA funded, Catalina Sky Survey, 60 inch telescope on Mt. Lemmon.  Without his efforts they would have likely been lost. These are only the most recent results of his work.  Over the years, his data have helped to establish the orbits of more than 4000 Earth approaching objects. Amazingly, his total accounts for more than 1/3 of known near Earth objects.

The location of the Great Shefford Observatory is not in an ideal climate.  However, it is at an ideal longitude, since it is dark there during the daytime in Arizona.  The large asteroid hunting surveys would lose track of many asteroids they find without followup observations which are carried out by other telescopes around the world. 

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

Go to travelersinthenight.org program 124 for more information.

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


More Information On This Program


125-NASA RADAR Finds Asteroid Moon

Published PRX February 26 , 2015
Recorded February 19, 2015

Click to Listen

Asteroid 2004 BL86 was discovered more than 10 years ago by the LINEAR program in New Mexico. 

Dr. Vishnu Reddy of the Tucson based Planetary Science Institute observed this small asteroid with the NASA Infrared Telescope Facility on Mauna Kea, Hawaii.  By measuring the colors which are present and missing in 2004 BL86's reflected light, he found it to have a composition similar to the Arizona sized asteroid Vesta. It is likely that 2004 BL86 was created when Vesta was involved in several massive collisions during which 500,000 cubic miles of rock were blasted into space.  The two large craters on Vesta's southern hemisphere are a record of these events.  Check out the NASA Dawn Spacecraft's images of Vesta.

Until recently, we knew asteroid 2004 BL86 only as a faint moving point of light in the night sky.   Early in 2015 it came close to planet Earth. RADAR images obtained with the 230 foot wide NASA Deep Space Network show that it is about 1100 feet in diameter and has a small moon about 230 feet across. 

Approximately 16% of the Earth approaching asteroids larger than a couple of football fields in diameter are really two objects in orbit about a common center of gravity.  The response to this type of double trouble object will be complicated should one of them be found to be on a collision course with planet Earth.

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

Go to travelersinthenight.org program 125 for more information.

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

More Information On This Program

126-Ready Yourself for Alien Life


Published PRX February 26 , 2015
Recorded February 19, 2015

Click to Listen

Carl Sagan said that "The Universe is a pretty big place.  If it's just us, seems like an awful waste of space".  It is hard to look into the sky on a clear dark night and not share this feeling.

Life occurs in the most hostile environments on Earth.  Liquid water occurs in other places in our solar system.  We are finding organic materials including amino acids and vitamin B3 in meteorites that come to us from outer space.

We now know that there are likely to be 25 Earth like planets in our Milky Way galaxy for every woman, child, and man on our planet.

Recently NASA and the Library of Congress sponsored a meeting focused on how humans might prepare for the discovery of life outside of Earth.  Dr. Seth Shostak of the SETI Institute told the group that we may discover past or present life on Mars, discover tell tale gases in other planet's atmospheres, or pick up signals from other civilizations.  Dr. Susan Schneider a professor at the University of Connecticut explored ideas concerning nonliving or artificial intelligence. 

In a recently published book, Dr. David Weintraub explores how people's religions will shape their reactions to the discovery of thinking beings outside of our planet.

Bottom line is that we cannot come up with a tight definition of either life or intelligence.
Many years ago Sir Arthur Eddington said "Not only is the universe stranger than we imagine, it is stranger than we can imagine"  Stay tuned.

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

Go to travelersinthenight.org program 126 for more information.

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


127-Tied for Third

Click to Listen

Published PRX March 6 , 2015
Recorded March 05, 2015

The appearance of a naked eye comet is one of natures most impressive displays. Humans have regarded these suddenly appearing objects as everything from a sign of an upcoming disaster, to the bringers of water and organic materials to Earth. In 1882 a Sun grazing comet was easily visible in the daytime and was nearly as bright as the edge of the Sun.  

Humans have discovered about 5,000 of the perhaps one trillion potential comets in our solar system. While most of the comets are discovered by large group efforts a significant number continue to be discovered by individuals.

Recently my Catalina Sky Survey teammate Alex Gibbs found his 27th comet. This discovery brings him into a tie for third place, in the list of observers, with my Catalina Sky Survey teammate Rik Hill.  

The rules for naming a comet are complicated and not completely consistent. Basically, if a person is the first to spot a moving object with cometary fuzz it receives their name. Sometimes there are two names attached to a comet especially if the objects discovery was made by a survey and it was first labeled to be an asteroid. In that case the person who discovered telltale cometary gases surrounding it has their name attached.

Not all comets are discovered with large telescopes and sophisticated electronic cameras. They sometimes sneak up on our planet by brightening suddenly. David Levy discovered 8 comets visually with small backyard telescopes. Perhaps, with persistence you too could discover a comet. 

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

Go to travelersinthenight.org program 127 for more information.

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


More Information On This Program

128-Buzzed By An Asteroid

Click to Listen

Published PRX March 6 , 2015
Recorded March 5, 2015

Recently my Catalina Sky Survey teammates Carson Fuls and Jess Johnson discovered a rapidly moving point of light in the sky. It was subsequently observed by telescopes in Italy, Arizona, New Zealand, and Australia. The Minor Planet Center used these data to calculate this object's size and orbit. It was given the name 2015 DD1.

Twenty six hours before humans spotted it, this 10 foot diameter space rock came within two and a half Earth diameters of our planets surface and was traveling at 8 miles per second. At that point it was bright enough to be seen in a small telescope had anyone been looking. In the future its orbit allows it to come to about 2,000 miles of the Earth's surface.

It is likely that 2015 DD1 will eventually enter the Earth's atmosphere producing an airburst of less than a kiloton to TNT. At night this would generate a spectacular light show and perhaps break a few windows if it happened over a populated area. It is likely that a tiny asteroid of this size enters our atmosphere fairly often. Most of the time such an impact occurs in the daytime or over the ocean and probably goes unnoticed. 

From 2000 to 2013 the Nuclear Test Ban Treaty Organization Network detected 26 explosions in the Earth's atmosphere which were created by space rocks. The NASA Fireball Network and other US facilities have recorded 556 events in which space rocks of various sizes have impacted our planet. 

Fortunately our atmosphere protects us from space rocks and harmful radiation.

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

Go to travelersinthenight.org program 128 for more information.

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


More Information On This Program

129-A 3 City Block Sized Asteroid



Published PRX March 12 , 2015
Recorded March 10, 2015

Recently my Catalina Sky Survey teammates Carson Fuls and Jess Johnson discovered an asteroid which comes close enough and is large enough be be classified as a Potentially Hazardous Asteroid.   It was subsequently observed by telescopes in New Zealand, Australia, Italy, Arizona, Pennsylvania, and Illinois and given the name 2015 DH155.

An asteroid of 2015 DH155's size is likely to strike the Earth every 60,000 years or so. Its orbit causes it to be traveling at 29,000 miles per hour when it crosses the Earth's path. If an asteroid like this were to impact on our planet it would release 10 times the energy of the most powerful hydrogen bomb ever exploded.  Such an event could make a crater several miles in diameter and damage trees and buildings over several thousand square miles if it happened over a land area.  

Asteroid 2015 DH155 travels once about the Sun in a bit less than 4 years on a path that takes it from out to well past Mars to near the planet Venus. For all but about 3 months every 4 years it is invisible to Earth' telescopes.  When humans discovered this 800 foot diameter asteroid, it was about 25 million miles from planet Earth and was traveling towards us a 9 miles/second. Fortunately, its orbit never brings it closer than about 16 times the Moon's distance from planet Earth.

Since DH155 will come near the orbits of Mars in July,  Earth in September,  and Venus in October of 2018,  the asteroid hunting community will be keeping track of it to determine that its path is not changed to make it a threat. 

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

Go to travelersinthenight.org program 129 for more information.

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


130-Things That Dim In The Night


Published PRX March 12 , 2015
Recorded March 10, 2015

Objects in the Universe that brighten rapidly grab our attention. One of the most spectacular examples is Kepler's supernova. In 1604 this star was bright enough to be seen with the naked eye in the daytime for over three weeks. Another occurred in 1843 when a comet became almost as bright as the limb of the Sun.  Over the centuries there have been many suddenly appearing objects in both the day and night sky. Possibly as the result of this history, most of the surveys which look for time variable objects in the sky are set to trigger on increases in brightness. 

Always one to think out of the box, Dr. Alice Quillen of the University of Rochester began to wonder if there are objects which dim in ways that will tell us about their natures.  She knew about eclipsing binary stars like Algol which dim on a regular basis and decided to look for other examples of things that dim instead of brighten.  She and her colleagues started by analyzing data on 40,000 calibration stars which were observed for about 4 years by the 2 Micron All Sky Survey.  They found a number new of members of known types of variables as well as some objects which are not easily characterized.  Although interesting, these results suggest that if one can apply a clever enough sorting tool to some large data bases which exist some exotic objects may pop out.  

The holy grail of this effort will be to find young stars and associated planets which have disks of material surrounding them.  The results will help us to find and understand  planetary systems in formation. 

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

Go to travelersinthenight.org program 130 for more information.

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


131-Deafening Silence


Published PRX March 19, 2015
Recorded March 12, 2015

More than 50 years of searching for signals from other civilizations in the Universe has produced a deafening silence. There is no evidence that aliens have visited the Earth or exist anywhere.  There are many hints that life might exist in other places but there is no conclusive proof that it does.  

Some argue that life is exceeding rare and that we are likely to be the only advanced civilization in our Milky Way galaxy.  They site the fact that we haven't discovered alien microbes, alien radio beacons, alien robotic spacecraft, alien markers on the moon  as indications that technological societies are not rampant in the Milky Way.  Professor Brian Cox of Manchester University goes even further and believes that the development of multi-cellular organisms and the extinction of the dinosaurs are so unique that intelligent life could not have happened twice in the Milky Way. 

The heavier elements like iron, sulfur, phosphorous, nitrogen, and carbon essential to life as we know it were forged in the interiors of the first few generations of stars in the Milky Way.   Further the frequency of life destroying gamma ray bursts was higher in the early universe than it is now.  These two facts make it more likely for life to develop in solar systems which have formed since about the time ours did.  

My money is on the concept that there are many planets which host living organisms.  Recent discoveries indicate that there may be as many as 40 billion habitable planets in the Milky way alone.  On some of them civilizations like are ours are likely to be emerging.  The physics of the Universe requires large allocations of energy and resources to become spacefaring.  Humans have so far dabbled in a few baby steps beyond our planet and made some attempts to listen for other beings.  What else is out there remains to be discovered.

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

Go to travelersinthenight.org program 131 for more information.

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


132-Kowalski's Forever Comet


Published PRX March 19 , 2015
Recorded March 12, 2015

My Catalina Sky Survey teammate Richard Kowalski has an instinct for discovering interesting objects.
Recently he spotted a fuzzy looking moving faint light in the night sky.  It was then observed by telescopes in Italy, New Mexico, and Texas and given the name C/2015 D5 (Kowalski). When Kowalski first spotted this comet it was traveling about 12 miles per second away from the Sun and was about 344 million miles from planet Earth.

About 14 months before Kowalski spotted it, Comet C/2015 D5 (Kowalski) was about 6 times brighter than it was on his discovery images.  It had gone un-noticed by human observers when it was closest to our planet at which point it was about two and a half times our distance from the Sun to us.  It could have been detected by a small backyard telescope and an electronic camera had anyone known where to look.    

We don't know if this comet dropped out of the Oort cloud of small cold objects which orbit far from our Sun or if it traveled into our solar system from the vicinity of a distant star.  However, its speed, direction, and the laws of Physics enable humans to predict where it will go in the future.

Currently it continues to move away from our Sun.  In the fall of 2035 C/2015 D5 (Kowalski) will continue to move into interstellar space and be further out than Pluto's average distance from the Sun.  At that point it will be traveling at a leisurely 6 miles per second in a direction between the constellations Libra and Scorpius. It is not heading towards any star in particular, however, if it was traveling at 6 miles/second in the direction of the nearest star it would take more than 130,000 years to get there. 

Comet C/2015 D5 (Kowalski) is likely to continue its cold lonely journey between stars till the end of time.

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

Go to travelersinthenight.org program 132 for more information.

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


133-2 Close Approaches

Published PRX March 26, 2015
Recorded March 18, 2015


Slightly more than a day apart, my NASA funded Catalina Sky Survey teammates Richard Kowalski and Carson Fuls  found two small asteroids. Both of them can travel to much closer than the distance to our Moon from planet Earth.  Subsequently, telescopes around the world were employed to determine accurate paths and size estimates for both of them. 

The first, Asteroid 2015 EO orbits the Sun every 1.47 years on a path which goes from the orbit of Venus to out past that of  Mars.  When Kowalski first spotted it, this 50 foot diameter asteroid was 4 million miles from Earth and was moving towards us at 9 miles/second.  Six days later it approached to about 3 lunar distances from Earth.  If it had been on an impact trajectory, we could have warned the people in danger to stay away from doors and windows. 

The second, Asteroid 2015 ET, orbits the Sun every 2.95 years.  When Fuls discovered this 50 foot diameter asteroid it was at nearly its closest point to Earth. After that it continued to move away from the Sun and Earth on a path that will take it 60% of the way to the planet Jupiter before it starts back towards the Earth again.

It is possible that either of these tiny asteroids could enter the Earth's atmosphere in the distant future and release the energy of a small nuclear weapon.  We might expect such an event every 27 years or so.  

There are likely to be several million space rocks of this size which come close to planet Earth.  We now know more about two of them. 

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

Go to travelersinthenight.org program 133 for more information.

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


134-Recycling Spacecraft



Published PRX March 26 , 2015
Recorded March 18, 2015

In the early days of space exploration when a flight component failed the mission was over.  In recent history, there have been a few times when astronauts have repaired satellites and a number of instances of Earth bound engineers reprogramming malfunctioning spacecraft so that they could continue their scientific work. 

For more than 25 years the Hubble Space Telescope produced unprecedented scientific data. This was made possible during repair missions by astronauts using the space shuttle.

The NASA Kepler Spacecraft has discovered more than a thousand planets orbiting distant stars.  When the second of its 4 stabilizing gyroscopes failed it could not longer point well enough to continue this effort.  Fortunately, clever NASA engineers figured out how to use the radiation pressure from the Sun to act as the third gyroscope.   The reprogrammed Kepler is now studying new exoplanets, stars of various ages, star clusters, and active galaxies.

The Spitzer Spacecraft and The NEOWISE Spacecraft are continuing to make scientific discoveries after their infrared camera's ran out of coolant by a clever reprogramming to extend their missions.   The malfunctioning NASA Wide-Field Infrared Explorer was reprogrammed to use its guide camera to determine the mass, compositions, and ages of more than 200 bright stars to a high degree of accuracy.  

Since the cost of developing and launching spacecraft far exceeds the cost of operating them for extended periods of time, our ability to recover from malfunctions allows scientists to make the best use of available funds.
 
For Travelers in the Night this is Dr. Al Grauer.

Go to travelersinthenight.org program 134 for more information.

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


135-Future Impact Possibilities



Published PRX April 2, 2015
Recorded March 31, 2015

Recently, three asteroids were discovered which have very slight probabilities of impact with planet Earth between 2065 and 2117.  My team, the Catalina Sky Survey found two of them and the Pan-STARRS group in Hawaii found the other one.   These three asteroids are some of the most recent objects to be listed on the NASA Sentry Risk Table.

It should be emphasized that the orbit of a small solar system object is never known perfectly.  Soon after discovery, an Earth approaching object's orbit is poorly known, since at that point, we have observations which cover a very small part of its path around the Sun. This is why objects which initially seem to be a threat are soon removed from that category with additional observations.

When a new object is discovered the observations of it are sent to the Minor Planet Center where they are posted on a public website.  Telescopes around the world observe it to refine its path in the sky.  After several days the new object's orbit is well enough known to allow us to keep track of it and an electronic publication is issued.  Within an hour or two the NASA Sentry software system calculates the impact risk that this new object poses to planet Earth.  If these preliminary calculations indicate a close passage is possible then a much more extensive set of calculations are performed to pin down possible impact dates over the next 100 years.   

So far so good.   

Maybe against the most incredible odds a small asteroid has our number on it.  

Maybe we will find it tonight.

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

Go to travelersinthenight.org program 135 for more information.

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


136-The Oceans of Ganymede



Published PRX April 2 , 2015
Recorded March 31, 2015

Ganymede was discovered by Galileo Galilei using his new telescope in 1610.  He observed it to be a faint point of light orbiting the planet Jupiter.  This discovery along with 3 of Jupiter's moons was the first instance of objects being observed to be orbiting another planet.

With a diameter of 3267 miles Ganymede (GAN'-ih-meed)  is the largest satellite in the solar system.  Surrounding its iron core are a sphere of rocky material and a thick layer of water and ice which extends to the surface of this small world. If Ganymede orbited the Sun instead of Jupiter it would be a planet in its own right. 

For more than 40 years, Ganymede has been suspected to have some liquid water below its frozen icy surface.  Recently the Hubble Space Telescope was used to study the auroras on Ganymede. These beautiful displays are similar to the northern and southern lights on Earth. These studies enabled scientists to use Ganymede's magnetic field to probe beneath its icy shell.  What they found is an ocean 60 miles deep covered by a layer of ice 95 miles thick.  This salty ocean contains more liquid water than exists on the Earth's surface.

Water is amazing stuff.  Water ice floats on top of liquid water.  This makes it possible for marine life on Earth to survive below a layer of ice which separates it from the hostile conditions in the air above.

Now that we know that Ganymede has a substantial salty ocean one has to wonder if some type of microbes might be living there. 

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

Go to travelersinthenight.org program 136 for more information.

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



137-Bad Seeing


Published PRX April 9, 2015
Recorded March 31, 2015

Looking at the Universe from the Earth's surface is a bit like a scuba diver viewing our world from the bottom of a swimming pool.  Don't get me wrong. I love our atmosphere. It gives us air to breath, keeps our body's fluids liquid, protects us from cosmic rays as well as space rocks, and performs many other functions which make life on our planet possible.

That being said the blanket of air which surrounds us makes it difficult to view objects in the Universe. On a night when the atmosphere is clear and not turbulent, the images of stars and asteroids are tiny points of light when imaged by our telescope's cameras.  Astronomers call this good seeing.  On other nights it can be perfectly clear but the images of faint asteroids and stars are spread out to the point that they blend into the night sky background.  This is what we call bad seeing. 

On a night of good seeing it is possible to spot faint Earth approaching asteroids.  On such a night members of my team, the NASA funded Catalina Sky Survey, have been known to discover more than a dozen Earth approaching asteroid candidates. On a night of bad seeing we some times don't find any.  These objects are likely to be there but we don't detect them since the bad seeing has blended them into the darkness of the night sky.

On a recent night of observing with the NASA funded University of Arizona 60 inch telescope the seeing was so bad and I did not find a single asteroid.  On the next night it was partly cloudy but the seeing was much better and I discovered 6 near Earth approaching asteroid candidates.

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

Go to travelersinthenight.org program 137 for more information.

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


138-An Inter-Planetary Visitor



Published PRX April 9 , 2015
Recorded March 31, 2015

Recently an inter-planetary visitor made a close approach to planet Earth.  It is about the same size as the object which entered our atmosphere in February of 2013 injuring nearly 1500 people in Chelyabinsk, Russia. 

When I first spotted this small space rock it was 2.6 million miles from planet Earth and was traveling towards us at 5.5 miles per second. After that it was tracked by telescopes in New Zealand, Germany, the Czech Republic, France, New Mexico, and Illinois. The Minor Planet Center used these data to determine its path around the Sun and gave it the name 2015 FF36.  The next day it came to about 5.6 lunar distances from our home planet.  It can come to within 20,000 miles of us which is closer than our communications satellites. It can also come to within 7.5 million miles of the planet Mars.

Dr. Alan Harris continues to analyze the Near-Earth asteroid population data and to calculate the number that are likely to exist in various size ranges.  His work indicates that there are several million Earth approaching asteroids similar to 2015 FF36. One similar to it probably enters the Earth's atmosphere every 40 to 50 years releasing perhaps 100,000 tons of TNT's worth of energy.

 One of the goals of the asteroid hunting community is to detect these small asteroids before they enter the Earth's atmosphere so as to be able provide a tornado like warning to people in the effected area so that  they will stay away from doors and windows. 

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

Go to travelersinthenight.org program 138 for more information.

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

 Fortunately it will not run into Earth in the foreseeable future.



139-Next Step To Mars



Published PRX April 16 , 2015
Recorded April 12, 2015

A trip to our Moon is one of the great human adventures of all time. However, 
such a voyage is but a small step of about 30 Earth diameters into the vastness of space.

NASA is proposing the next step on the path to Mars to be a mission to an asteroid or a 
boulder taken from the surface of an asteroid. These are objects, which have been 
previously captured and, placed into orbit around our Moon. Such a voyage would 
take 4 times longer than an Apollo mission and would gain valuable experience with 
solar electric propulsion, a new generation of space suits, and other vital components 
of a manned Mars mission.

One candidate for the boulder mission is 2008 EV5. It was discovered by my team, 
the NASA funded Catalina Sky Survey's 60 inch telescope on Mt. Lemmon in Arizona. 
By measuring the colors that are present and missing in the light that this asteroid 
reflects, astronomers have determined that it has a composition similar to a meteor 
which fell in France in 1864. This rare type of space rock has, with the exception 
of the gases hydrogen and helium, has the same composition as the Sun.
 It is thus a sample of the primitive material which came together to 
form our solar system.

Radar observations show 2008 EV5 to be roughly a sphere having a diameter of 
about 4 football fields. It has a crater about 1/4 of its diameter indicting a major 
collision in the past. A visit or a sample and return mission to this small world 
will provide a mother load of information about the history of our solar system. 

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

Go to travelersinthenight.org program 139 for more information.


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



140-A Weird Orbit


Published PRX April 16 , 2015
Recorded April 12, 2015

The vast majority of asteroids orbiting the Sun do so on a path that is pretty much 
in the same plane as the planets.  There is a lot of empty space in the solar system, 
however, we see asteroids with craters on them so we know collisions have occurred.  
It seems likely that an asteroid whose path is highly inclined to the plane of the
solar system was involved in a collision with another object causing a radical change
in its orbit.  

Recently the Pan-STARRS group in Hawaii discovered a potentially hazardous 
asteroid, 2015 FS332.  Its orbit  is inclined by 35 degrees with respect to the ecliptic, 
where the planets and most asteroids travel. It is a large one with a diameter of 
about 750 meters.  One like this probably hits the Earth every few hundred thousand 
years or so releasing  300 times the amount of energy of the largest hydrogen bomb 
ever exploded.  Fortunately asteroid 2015 FS332 never comes closer to planet Earth 
than about 16 times the distance to our Moon. The near Earth asteroid community 
has discovered several hundred asteroids of this size which come near the Earth. 
However, there are still a few out there that we don't know about yet.

The Pan-STARRS group in Hawaii and my team the Catalina Sky Survey in Arizona 
are part of the NASA's Near Earth Object Program.  The goal of this effort is to provide
 a warning should any object be on a collision course with planet Earth.  
Serious scientific and engineering studies are underway to determine the best 
way to mitigate such a disaster. 

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

Go to travelersinthenight.org program 140 for more information.

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


141-Sailing the Cosmos


Published PRX April 23 , 2015
Recorded April 12, 2015

The first human use of the wind to power boats most likely occurred in about 3,000 BC.  This was a major improvement in travel over walking and animal drawn carts.  

About 400 years ago the German astronomer, Johannes Kepler, observed that Comet tails were being moved by what he thought might be a Solar breeze. He suggested that this phenomena could be used to power ships through space. In 1873 James Clerk Maxwell demonstrated that photons from the Sun exert a small force as they bounce off of a reflective surface.  Recently the Kepler Space Craft began to use this tiny light pressure to maintain its orientation after the 2nd of its 4 stabilizing gyroscopes failed. 

The Planetary Society has initiated and funded the LightSail  It is a loaf of bread sized spacecraft which will hitch a ride aboard a rocket being launched on another mission.  Once in orbit this tiny spacecraft will deploy a 4 panel solar sail which is about 5.5 meters on a side. 

Three or four hundred years from now humans may send a robotic space probe to a nearby star using a light sail as big as the state of Texas.  Ideally it would deploy its giant solar sail near the Sun perhaps as close to it as the planet Mercury.  This would give it maximum initial thrust.  After it gets far from the Sun it could be pushed along by a powerful pinpoint laser beam.  Theoretically it is possible to achieve a fraction of the speed of light through this means.

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

Go to travelersinthenight.org program 141 for more information.

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


142-Planetary Defense


Published PRX April 23 , 2015
Recorded April 11, 2015

Recently people from all over the world met in Italy to discuss ways that humans can prepare for the unlikely, but not impossible, situation that an object is on an impact trajectory with planet Earth.   They were were presented with a hypothetical asteroid threat.   

On the day of its discovery the hypothetical asteroid is a faint moving point in the night sky.  A few days of observation provides it with a tentative orbit and it is given the name 2015 PDC.  It is the smallest of the Potentially Hazardous Asteroids with a diameter between 100 and 500 meters.  As observations of its path in the sky continue, it appears to have a tiny increasing chance of impacting Earth.  If it did it would be traveling at 7 miles/second and pack the energy several times greater than the most powerful hydrogen bomb ever exploded.  As with all real asteroids this hypothetical object's size and composition are not known with any degree of precision. 

 A month after its discovery the hypothetical asteroid comes about 18 million miles from us . It continues to be observed for another month with every new observation making it appear to have a greater chance of colliding with mother Earth about 7 years hence.  This is where the participants are left.  At this point they don't know its exact size, chemical composition, if it will collide with us or not, and if it does the spot of impact on Earth.  They are then charged with the task of obtaining needed observations and to develop a strategy to deal with the potential impact.

We will just have to see what this group of experts can come up with.

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

Go to travelersinthenight.org program 142 for more information.

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


143-Busy Little One


Click to Listen

Published PRX April 30 , 2015
Recorded April 20 , 2015

Recently my Catalina Sky Survey teammate Rik Hill discovered an asteroid about the size of a luxury sedan which cruises about the inner solar system.

When Hill found it this tiny space rock was about 750,000 miles away and was traveling at 7 miles per second towards us. The day after its discovery this small asteroid passed between the Earth and Moon. During this period of time it was observed by telescopes in New Zealand, Japan, Estonia, and Hungary. The Minor Planet Center gave it the name 2015 GU. 

This 20 foot diameter asteroid orbits the Sun every 3 years. We don't know how long ago it was placed into this orbit.  If we could get a piece of it we could read its internal clocks. For example, by analyzing fragments of the space rock which entered our atmosphere over Chelyabinsk, Russia we know it had collisions 30 million and 2 million years ago which put it on a path to impact planet Earth.

Scientists at JPL and NASA have calculated this small asteroids path through space. From 1902 till the time of its discovery it made close approaches 14 times to Earth, 4 to Mars, and once to our Moon. Between 2023 and 2129 it will make 9 close approaches to planet Earth.

It is unlikely that 2015 GU will enter our atmosphere. If it did it would probably disintegrate before reaching the surface releasing the energy of several thousand tons of TNT. In the meantime 2015 GU will continue to travel the inner solar system until it collides with another object in the far distant future.

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

Go to travelersinthenight.org program 143 for more information.

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

More Information On This Program

144-One Of A Million

Click to Listen

Published PRX April 30 , 2015
Recorded April 20, 2015

Recently I was observing with the NASA funded Catalina Sky Survey 60 inch telescope on Mt. Lemmon when the computer identified a faint fast moving object in the night sky. Not being sure it was real I scheduled followup observations. About an hour later the second set of observations showed that it is a real object. On the next two nights this small space rock was observed by telescopes near Westfield, Illinois and on Kitt Peak in Arizona. These observations allowed the Minor Planet Center to determine an orbit and a tentative size. It was given the name 2015 GB.

2015 GB is about 60 feet in diameter. Amazingly, the equipment was able to detect it when it was over 4 million miles away and traveling towards Earth at more than 7 miles/second. Six days earlier it had been about half that distance away from us but nobody had spotted it. At some point in the future the motion of this small asteroid and our planet will allow it to come to about 150,000 miles from us.

Dr. Al Harris continues to study the properties and discovery statistics of the near Earth  
asteroid population. His work indicates that there perhaps as many as 10 million space rocks like 2015 GB which come close to Earth. So far we have have discovered only a few thousand of them. The problem is that, most of the time, they are too faint to be detected by our telescopes.

We hope to find ones this size that are on an impact trajectory with planet Earth so as to be able to warn people to stay away from doors and windows. 

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

Go to travelersinthenight.org program 144 for more information.

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


More Information On This Program

145-Near Earth and Moon


Click to Listen

Published PRX May 6 , 2015
Recorded May 3, 2015

Recently my Catalina Sky Survey teammate, Rose Matheny discovered a tiny asteroid that passed 115,000 miles from Earth and 104,000 miles from our Moon.

When Rose found it streaking through the night sky it was 750,000 miles from her and moving towards Earth at nearly 9 miles/second. 23 hours later it made its closest approach to us. The next day as it continued to move towards the Sun, it faded from view as the fraction of its lighted side visible to us continued to shrink. It was bright enough to see with Earth's telescopes for about a week. During this brief time it was observed by telescopes in Hawaii, Hungary, Italy, and England. The Minor Planet Center gave it the name 2015 GL13

This little guy orbits the Sun every 3.6 years on a path which takes it slightly inside of Earth's orbit to out to between Mars and Jupiter. It can come as close as 8 Earth diameters from our planet's surface. There are likely to be more than 100 million small space rocks the size of this one that come near us.  

If 2015 GL13 ever did enter the Earth's atmosphere it would likely release the energy of about 4,000 tons of TNT. This would produce quite a light show if it happened at night and perhaps break some windows if it came in over a populated area.

Rose's discovery demonstrates the fact that the asteroid hunting community is beginning to have the ability to discover small space rocks before they make their closest approach to Earth. 

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

Go to travelersinthenight.org program 145 for more information.

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


More Information On This Program

146-Stuff of Life

Click to Listen

Published PRX May 6 , 2015
Recorded May 3, 2015

Evidence from comets and meteorites has brought many scientists to believe that the basic building blocks of life were brought to Earth by small bodies which impacted our home planet early in its history.    When and where did the substances, including water and organic materials required for life as we know it, appear in our solar system? 

Recently we got some important clues from the Atacama Large Millimeter/submillimeter Array or ALMA which is a located about 9,500 feet above sea level in the high dry desert of northern Chile. Astronomers pointed this powerful radio telescope in the direction of  the star, MWC 480, in the constellation of Taurus. The star MWC 480 has coalesced very recently from a cold dark gas cloud and is surrounded by a disk of material from which planets may eventually form.  

Astronomers focused a portion of ALMA's 66 individual radio dishes on a region in this new solar system far from its parent star.  They chose this place because it is very similar to the realm of small icy planetoids and comets which is located beyond the planet Neptune in our solar system.   In doing so they discovered enough methyl cyanide to fill all of Earth's oceans.  This organic molecule contains the carbon-nitrogen bonds which are required to form amino acids and proteins. 

It thus appears that when planets form around MWC 480 that they will be seeded with the building blocks of life from the comet forming region in this baby solar system. 

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

Go to travelersinthenight.org program 146 for more information.

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

More Information On This Program

147-High Traffic Area

Click to Listen

Published PRX May 14 , 2015
Recorded May 3, 2015

Francesco Manca of the Sormano Astronomical Observatory is doing some of the important work of keeping track of the asteroids which can make close approaches to our Earth, our Moon, and other objects in space.  He has compiled the fact that the asteroid hunting community has found more than 2000 small asteroids, of less than several football fields in diameter, which can make close approaches to us.  Nearly 700 have orbits which allow them to come closer to the Earth than our Moon.  So far more than 250 of these small asteroids have come or are predicted to come less a lunar distance from our home planet. 

A recent one of these very close approaching objects was discovered by my NASA funded, Catalina Sky Survey teammate Carson Fuls.  It is about 35 feet in diameter. Not long ago it passed about 4 Earth diameters from the Earth's surface. During this time it was observed by telescopes in Arizona and Chile.  It orbits the Sun every 3.3 years and will come near the Earth again in 2099, 2106, and 2113.  About every 100 years or so it comes close enough to the massive planet Jupiter to have its motion effected by it.

Another somewhat larger asteroid was discovered when it was far away and faint by astronomers using a 4 meter telescope in Chile. It may come near to us and our Moon in a few months.  We will not know much about the details of its close approach until it gets brighter and the asteroid hunting community is able to obtain more observations to pin down its path in space.

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

Go to travelersinthenight.org program 147 for more information.

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


More Information On This Program

148-Radio Eyes

Click to Listen

Published PRX May 14 , 2015
Recorded May 3, 2015

Human eyes are sensitive to wavelengths or colors in a small portion of the electromagnetic spectrum.  

If you woke up tomorrow morning with radio eyes your surroundings would look very different. Invisible to us, are the radio waves occupying a vast region of other wavelengths.These invisible radio waves are produced by a number of very interesting physical processes in the Universe. In fact how things look would depend on the part of the radio spectrum that you could see.

The Sun is the brightest object at most radio wavelengths.  To your radio eyes, the rest of the sky would contain many surprises.  

The Moon and planets do not shine by reflected radio waves from the Sun but glow because of their thermal radiation making them look quite different to your radio eyes.

Your radio eyes would not detect most of the bright stars familiar to us even though they are part of our Milky Way galaxy and are located within a few hundred light years of planet Earth. 

Instead the "bright stars" seen by your radio eyes would be quasars which are emitting radiation from the vicinity of super massive black holes at the centers of galaxies.  Amazingly enough the radio bright quasars are located, on average,  5 billion light years from us. 

One your radio eyes strangest sights would be the glow that you would see in every direction.  It is the Cosmic Microwave Background radiation from the Big Bang. It is the strongest component of all electromagnetic radiation, fills the Universe,  and marks the beginning of the Universe as we know it. 

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

Go to travelersinthenight.org program 148 for more information.


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

149-Near Venus to Past Jupiter



Published PRX May 21 , 2015
Recorded May 10, 2015


About a month before my Catalina Sky Survey teammate Rik Hill spotted it,  a 5 football field diameter asteroid had been almost as near to the Sun as the planet Venus.  His discovery images showed it about to cross the Earth's orbit at a speed of 21 miles per second coming towards us.   Additional observations by telescopes in Illinois, New Mexico, and Arizona showed that its 7.6 year path around the Sun will take it out to well past the planet Jupiter. This object's orbit is highly elliptical and inclined so that it moves above and below the plane where the planets and nearly all of the other solar system objects exist.  It had crossed the Earth's orbital path moving towards the Sun about 6 weeks before it was discovered but nobody noticed it since it was faint and far away from Earth. 

About 6 years from its discovery it will be once again traveling towards the Sun as it crosses the Earth's orbit at a speed of 10 miles per second relative to us.  Its path never brings it closer than about 14 times the distance to our Moon from our home planet.  This is a good thing since this asteroid is 10 times larger than the object which killed 80 million trees over an 800 square mile area at Tunguska, Russia in 1908.

The asteroid hunting community has discovered nearly 1600 potentially hazardous asteroids which are larger than several football fields in diameter and come to less than 5% of the distance to the Sun from Earth.   Fortunately we have not discovered any large objects like this one which are on an impact trajectory with planet Earth.

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

Go to travelersinthenight.org program 149 for more information.

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


150-How Big It Is

Click to Listen

Published PRX May 21 , 2015
Recorded May 10, 2015

Asteroids are moving points of light in the night sky, which shine by reflected Sun light.  The asteroid hunting community determines a new object's orbit around the Sun by continuing to measure its changing position in the sky.

A very few of the known asteroids have come close enough to bounce RADAR beams off of or have been visited by spacecraft.  In these rare cases we have direct measurements of an asteroids size and shape. For the vast majority, however,  we can only estimate the size of an asteroid by comparing its brightness with nearby standard stars to determine a calibrated brightness for it.   The asteroids calibrated brightness combined with our knowledge of the Earth's orbit, the asteroids path in space, and an assumption about the percentage of Sun light that it reflects allow us to estimate this tiny point of light's physical size.  It is also possible to determine an asteroid's shape by repeatedly measuring it brightness as it spins on its axis and moves about the Sun.

Dr. Arlo U. Landolt of Louisiana State University has spent more than 30 years establishing a network of standard stars around the sky which are used to calibrate the measurement of the brightness of objects in space.  He has conducted his observations using telescopes principally in Chile and Arizona.  Dr. Landolt's Standard Star observations are an important key to our understanding of physical processes occurring in the Universe.

The next time you hear someone state the size of an asteroid it is a safe bet that it based on Dr. Landolt's Standard Star measurements.

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

Go to travelersinthenight.org program 150 for more information.

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

More Information On This Program


Comments