March Sky Notes
Written by John Stapleton
Image Credit: StarWalk
A Bright Comet?
Recent observations of the comet 12P/Pons-Brooks have shown it to be in outburst. This comet is a periodic comet, that is, one that is known to return on a regular basis. For Pons Brooks that period is every 71 years. The most famous periodic comet is Comet 1P/Halley which has a period of between 76 and 79 years and is not due to return to our skies until 2061. The long periods of these comets is due to the highly elliptical shape of their orbits which carries them out into the far reaches of the Solar System.
Pons-Brooks is also regarded as one of the brighter such comets, as it sometimes increases in magnitude considerably, as it approaches the Sun. The comet was first discovered by French astronomer Jean-Louis Pons, in July 1812 but has also been identified (by tracing its orbit back through time) as one seen in 1385 and again in 1457. The comet was recovered in 1884, as predicted, by American astronomer William Brooks when it underwent an outburst making it a naked-eye object. In 1954 the comet again underwent several outbursts but only became bright enough to be seen in binoculars. At the beginning of this month, the comet can be found above the square of Pegasus amongst the stars of the constellation Andromeda and over the course of the month will track Westwards so that it finishes the month amongst the stars of Aries quite low in the North-Western sky. The comet actually reaches perihelion (the closest point in its orbit to the Sun) on 21st April and its Perigee (closest point in its orbit to the Earth) on 2nd June, when it will be seen in the morning sky. The Comet is a Solar System object and is actually much closer to the Earth than any of the stars mentioned in this description. At perigee the comet will be just 232 million Kilometres (One and a half times the distance between the Sun and the Earth) from our planet.
In other space news, the American private company, Intuitive Machines, successfully landed the first American craft on the Moon for over 50 years at the end of February. Success has been measured as achieving a soft landing in the target area and sending a radio signal back to Earth. There was an unexpected delay in the transmission of the signal, probably due to the fact that the lander, named Odysseus, toppled over onto its side after touchdown. It is hoped that the onboard instruments can still accomplish their tasks before the craft freezes to death in the oncoming lunar night in the first two weeks of the month.
Sky Notes
Please note all times given in this article are in GMT and as the clocks have changed that is the current time.
See March Sky Schedule
Sun: From the beginning to the end of March the hours of daylight increases from 11 to 13 hours. The Spring or Vernal Equinox (the day when night and day are of equal length) occurs on March 20. The clocks go forward by 1 hour to British Summer Time at 02.00am on March 31st.
Mercury: Mercury reaches its greatest Eastern Elongation (distance from the Sun, as we see it) on 24th and so is in the best possible position to observe this elusive planet. As Mercury is the closest planet to the Sun, it is often lost in the glare of the Sun. At its greatest elongation, Mercury is briefly visible low in the Western sky after the Sun has set below the horizon. The sky will still be quite bright but, with the Sun out of the way, it will be safe to search the sky with binoculars or a telescope. Follow a line down from the much brighter Jupiter towards the point where the Sun set and you should be able to spot Mercury.
Venus: Venus is not visible this month as it lies on the other side of the Sun from the Earth.
Mars: Mars is also no longer visible.
Jupiter: Jupiter dominates the evening sky until it sets around 10.30pm. The giant planet is seen against the background stars of Aries. With a large pair of binoculars or a small telescope you should be able to follow the movement of the planet’s four largest moons, Io, Europa, Ganymede, and Callisto that were discovered by Galileo in 1610 when he observed them whilst first using his telescope.
Saturn: Saturn is no longer visible.
Uranus and Neptune: Uranus is seen against the background stars of Aries about a third of the distance from Jupiter towards the Pleiades star cluster. At magnitude 5.8 it is visible in binoculars. Look for a tiny greenish disc compared to the pinpoints which are the stars. Neptune is in conjunction with Sun and is not visible this month.
Meteor Shower: There are no regular meteor showers this month. However stray or sporadic meteors can still be seen at any time. Some of these can be very bright. One of the largest and brightest asteroids is visible below the constellation of Leo this month. The asteroid 3 Juno (because it was the third one discovered) should be a binocular object but will appear just like any other star. If you are able to view and memorise or image the pattern of stars over several nights you will notice that one of the points of light will move relative to the others. This is the asteroid.
Comet: Comet 12P/Pons-Brooks is set to become, at least, a binocular object this month (see main article)
ISS: The International Space Station will be visible for a duration of some 6 minutes, twice this month. The first apparition will be on 19th between 19:03 and 19:10 from West-South- West until it disappears at East-North-East, and the second is on 21st, following the same track.
The Third Quarter Moon occurs on March 3rd with New Moon on 10th, First Quarter then follows on 17th March and Full Moon on 25th.