Comet Lovejoy is on the Way

Comet C/2014 Q2 (Lovejoy) was discovered in August 2014. Observers in the southern Hemisphere could see it throughout the last quarter of 2014. By December 2014 the comet could be seen in binoculars or a small telescope as a faint blob with a fainter still.

ISON ought to be more spectacular to see than Comet Lovejoy, visible near Earth's horizon in this nighttime image photographed by NASA astronaut Dan Burbank, Expedition 30 commander, onboard the International Space Station on 22 December 2011. (Image credit: NASA )

Astronomer Terry Lovejoy has discovered five comets to date. Sadly C/ 2014 Q2 will probably not be as spectacular a sight as Comet C/ 2011 W3 (Lovejoy), visible near Earth’s horizon in this nighttime image from the International Space Station on 22 December 2011. (Image credit: NASA )

 

The comet spent the last few days of 2014 in the constellation of Lepus (the Hare) . You needed to stay up until midnight and look south. By the end of December the comet was just visible to the unaided eye. The comet made its closest approach to Earth on 7  January 2015, at a distance of 72 million km (45 million miles).  In January the comet will race though the constellations Eridanus, Taurus, Aries and Triangulum. On the night of 19 January 2015, Q2 Lovejoy will pass close by the Pleiades.

I saw the comet myself on 12 January 2015. Around 7pm, against a dark sky it was just visible to the unaided eye as a grey smudged-looking star forming the third vertex of a triangle with M45 and Aldebaran. Looking through 15×70 binoculars revealed the greenish-grey coma and I believed I could discern the faintest hint of a wispy tail. The green colour of the coma is emitted by molecules of diatomic carbon glowing  in ultraviolet sunlight.

Oddly later that evening (10pm) when it was higher in the sky I found it much harder to locate by eye, though I could easily see it with the binoculars. It is certainly worth going outside and braving the cold for a once in a lifetime look at this little visitor from the depths of space. Do not leave it too late; it is as about as bright as we are going to see it at the moment.

The comet originally orbited the Sun every 13 500 years or so, with its furthest point (called aphelion) more than 170 billion km (1130 AU) away in the Oort Cloud. This elongated orbit is inclined at 80.3 degrees relative to the ecliptic (the plane the planets orbit in). The comet will be closest to the Sun (perihelion) , on 30 January  when it will be 193 million km from the Sun. As it passes through the Solar System C/2014 Q2 Lovejoy’s orbit has been slightly altered by the gravity of the planets, it will next return in 8000 years. I wonder what sort of show it will but on then and what eyes will watch it.

NOTE: THIS COMET IS NOT GOING TO HIT THE EARTH. IT WILL NOT CAUSE ANY HARM TO OUR PLANET.

(Sorry for shouting but to my amazement and horror people are already asking if they should be worried by this comet.)

(Article by Colin Johnston, Science Education Director. Updated 13 January 2015)