The new year period offers us a rare chance for a beautiful sight: a new comet that was recently discovered as gravity brought it around the sun.
Comet Catalina, while not visible to the naked eye, can be seen using binoculars, in the morning sky. It has a pale silvery colour.
Photos of the comet abounded in the first weeks of last month, before the moon lit up the sky and blew out the comet’s dim light. In fact, photos show two long tails that the comet developed as it passed around the sun on November 15, 2015, at a distance of 122 million kilometres.
Comet C/2013 US10 Catalina was discovered in October 2013 from Catalina Observatory in Tucson, Arizona, US. Since then, it has approached the sun and been the subject of various studies by astronomers during 2014 and 2015.
As the days went by it has been rising above the eastern horizon as it moves away from the sun and is now high in the sky on the borders of Bootes and the Big Dipper constellations. It will be closest to the Earth on January 17 at a distance of 108 million kilometres.
It will be followed by astronomers up to around next March, when it then will become too dim as it cools down and exits the solar system. The two tails will eventually recede as they too fade away. On the other hand, however, the passage of this comet will serve to show how, in the immensity of space, things change, even over the course of a few years.
This month will also see the return of the giant planet Jupiter in the evening sky. Even a pair of binoculars will show its four bright moons discovered by Galileo in 1610. A telescope will show the cloud bands on the planet and shadows cast by the moons onto the planet itself and its turbulent atmosphere.
By the end of the month Jupiter will rise at around 8.30pm in the east. During February it will continue to brighten as it approaches its brightest phase in early March. It is very easy to spot as it will be the brightest point source of light in that part of the sky, at that time.
Nearby in the sky, the constellation Orion is something that should not be missed. If you have never tried to recognise the constellations, now is a good time. The skies get dark early, even though we are now having longer days and shorter nights as from the first day of winter, last month.
The three stars in a row towards the south are the unequivocal tell-tale star formation of Orion’s belt. Just below these three stars, and clearly visible to the naked eye, from a dark-sky site, looking like a small milky cloud, is the Orion nebula.
Known also to astronomers as M42, this immense gas cloud has been known to sky gazers since antiquity and has been observed through telescopes over the past 400 years. At a distance of 1,500 light years, the nebula has existed for the past few hundred thousand years. One light year is equivalent to well over 9,000 billion kilometres – the distance covered by a ray of light over the course of a year.
The Orion Nebula is one of the largest gaseous clouds of our own galaxy, the Milky Way. It is around 50 light years across and its mass is equivalent to that of hundreds of stars. Its luminosity comes from the birth of massive stars at its core, so-called ‘supergiant’ stars. This is what makes it perceptible to the naked eye even when the moon is up.
Astronomical events
Yesterday, 6.30am: Last quarter moon; 11.59pm Perihelion: Yesterday the Earth was closest to the sun in its orbit.
Today, 7.45pm: The moon close to the planet Mars.
Tomorrow early morning: Quadrantid meteor shower maximum.
Thursday: The moon close to Venus and Saturn (morning sky).
Saturday (morning sky): Planets Venus and Saturn close together.
Next Sunday 2.30am: New moon.
January 17, 0.26am: First quarter moon.
January 24, 2.46am: Full moon.
Alexei Pace is president of the Astronomical Society of Malta.