Last night I watched an asteroid --- 2004 BL86 --- drift past the Earth. There was never any danger of a collision and it never got closer than about 3x the distance of the Moon. Nevertheless it was an interesting event to watch through the telescope. The asteroid was tracking north through the evening sky. At around 7.30pm, when I arrived home from work, it was too low in the southeast sky in Hydra. As the evening went on it raced north towards the constellation Cancer.
The animation below was made from frames taken over a ten minute period at around 9.30pm. The asteroid moved across a patch of sky about the size of the full moon during this period.
I stacked the images to make this picture:
I'm not sure why the asteroid has a strong green colour! It may be that the presence of moonlight in the sky messed up the colour balance during post processing.
Just to put this into some kind of perspective: the asteroid is about half a mile in diameter and it was around 1 milliion miles away when I took the pictures. Shining at around 9th magnitude, the asteroid was much too faint to be seen without optical aid. I saw several articles on astronomy and science websites suggesting that binoculars would have been enough. The fact of the matter is that at least a small telescope would have been needed by most observers unfamiliar with searching for faint objects.
Radar surveys of the asteroid carried out yesterday showed this tiny asteroid had a moon!
This is second time I've caught an asteroid close approach. I was lucky enough to catch the even closer approach by an asteroid called Duende (formerly 2012DA14) in 2013.
Comet 2014 Q2 Lovejoy will be at its closest point to the Sun on January 30th - a mere 120 million miles from it. Despite being further from the Sun (by 27 million miles) than us, Comet Lovejoy is glowing in our northern sky more brightly than any comet since Comet 2011 L4 PANSTARRs in 2013. Comet Lovejoy is starting to fade but remains excellently placed in the northern sky for UK astronomers.
The chart below shows the path of Comet Lovejoy from the last week of January until the start of March. During this period the comet is expected to fade from magnitude +5 to +8. Comets are somewhat unpredictable and those estimates don't take account of sudden outbursts caused by unstable conditions on the comet.
During the past few weeks I've tried to get pictures of Comet Lovejoy on lots of occasions. Here are a couple of my best pictures:
That delicate ion tail has been very difficult to see both visually through the telescope eyepiece and on camera. It's not helped that someone thought it a good idea to build Newcastle not far from here. And even less of a good idea to fill it with streetlights. Makes it almost impossible to get dark skies from my back garden.
The comet begins February in the constellation Andromeda, near second magnitude star Almach (itself a superb double star through telescopes). An excellent photographic opportunity occurs on the evening of February 20th/21st when the comet will be very close to the Little Dumbbell nebula (M76) in Perseus.
During March the comet will fade to the point where only telescopes can resolve the coma as it begins to blend into the rich starfields of Cassiopeia.
Patrick Moore poularised the star pattern called the Summer Triangle in books and on The Sky at Night from the 1950s on. A less well known asterism for this time of the year is the Winter Hexagon. Here it is!
The mathematical part of my brain says No! Seven stars makes seven sides! That should be Winter Heptagon! But before it gets too carried away about the exact nature of the shape...it's already too well known as a hexagon to change it now. I suppose two of the stars are almost on a straight line. Enough.
It's a huge asterism. The angular distance between the top (Capella) and bottom (Sirius) is around 66 degrees. Capella is almost overhead in the UK during winter evenings, while Sirius is low above the southern horizon.
Here are some factoids about the seven stars of the WInter Hexagon:
Much of the constellation Orion is contained within the Winter Hexagon. Looking at the shape I feel that Betelgeuse should somehow be included - a brightest star inside it but offset from the centre.
Just to put the WInter Hexagon into context - here is a Stellarium rendition of the sky with the familiar constellations in place along with the Hexagon.
Comet 2014 Q2 Lovejoy is really starting to put on a great show for UK astronomers. At last, it is north of the celestial equator and shining brightly enough to be visible to the naked eye. My camera remote control has died so the pictures below were taken with my dad's superior Nikon D90.
This was my view of the southern sky at about 6.30pm last night:
Comet Lovejoy was easily visible in the sky. At first glance it looks like a faint star but using averted vision it does look somewhat fuzzy. The cometary nature is revealed easily with binoculars.
A closer view of Comet Lovejoy as it passes through a beautiful part of the sky near Taurus, the Bull.
Finally, here's a telescope view of the comet revealing many delicate streams of material pushed away from the comet by the solar wind.
Comet Lovejoy was about 45 million miles from Earth last night. Although it's getting further away from us, it is continuing to approach the Sun. It will remain an easy target over the next couple of weeks for binoculars and small telescopes.
The clouds cleared for a couple of hours yesterday afternoon and I got a chance to see Mercury catching up to Venus in the evening sky. This was the view from my garden in Red Row.
The distance between them was about half a degree; closer than your little finger at arms length! You can just about see my telescope in the foreground of the picture. When I put the camera on that I got this view:
Venus is much brighter than Mercury. Both planets are almost behind the Sun as seen from Earth but Mercury is nearest to us. However, Venus is much bigger and has very reflective clouds whilst Mercury has no atmosphere and a dark, dusty surface. The upshot is that Venus always outshines Mercury.
This year promises to be a bumper year for astronomy events and space exploration.
It's already off to a good start with Comet Lovejoy in the evening sky. In January and February the comet should be quite easy to see with binoculars and telescopes as it heads north of the equator. Probably visible to the naked eye during January away from town and city lights.
In March a NASA mission to explore new worlds will reach a milestone. The Dawn spacecraft has spent a few years in the asteroid belt between Mars and Jupiter. Dawn spent a year orbiting and mapping Vesta, one of the largest asteroids. After leaving Vesta, Dawn has coasted out to meet the biggest asteroid of all: Ceres. Not that much is known about Ceres at present. It may turn out to be the core of a rocky planet that never got the chance to grow into a big rocky planet like Earth did.
Another NASA mission called New Horizons will complete its 9 year journey in July when it zips by distant planet Pluto. When I was young Pluto was basically an unknown dot in photographs. Initially thought to be Earth sized, astronomers now know it’s smaller than our moon. It also orbits in a region of space brimming with similar icy objects. Astronomers re-classified Pluto as a Dwarf Planet some years ago. New Horizons will at least show us this bizarre world in close up for the first time and send back images of Pluto and its system of at least five moons.
During 2015 Rosetta will continue to orbit the comet as it approaches perihelion. Perhaps it will witness a flurry of activity as the Sun warms the surface of the comet. It remains a possibility that the Philae lander might reawaken if the changing position of the comet and Sun can recharge the ailing lander's battery.
In the early hours of September 28th another total eclipse – this time lunar – as the moon passes through the shadow of the Earth. Not all of the light is blocked and sunlight is reddened by our atmosphere and bent towards the moon, turning it orange and red for more than an hour.
The planets will put on a nice show at various times in 2015. During January the planets Mercury, Venus and Mars will make a nice group in the western sky after sunset. And on mornings in late October there'll be a chance to see Mercury, Venus, Mars and Jupiter in the eastern sky before sunrise. In all there will be a least 12 observable planetary conjunctions in 2015.
Of the meteor showers this year - it's going to be good year to see the Perseids in August. The peak of the shower occurs two days before New Moon. The December Geminids take place a couple of days after New Moon this year. That should ensure lots of shooting stars are visible near the peak.
All of these events are coming this year along with the usual planetary gatherings, meteor showers and with luck – the northern lights!
If you glance towards the southwest at around 4.30pm to 5pm you shouldn't have too many problems spotting the planet Venus. Over the coming months it'll gradually get easier to see as the Venus-Sun-Earth angle widens and the planet climbs higher into the evening sky.
Here's a picture I took from an upstairs window at home about 45 minutes after sunset. Venus is pretty obvious, just beneath the three telephone cables.
During the next couple of weeks the smallest planet in the solar system will join Venus. In fact the camera picked up Mercury this evening. It's already in the same part of the sky and my camera managed to capture enough photons of light from Mercury to register in the picture above. I've cropped and enhanced the region with both planets to try and bring out Mercury more clearly:
I didn't see Mercury visually or through the camera lens. I think I would've been able to see it about 10 minutes later after the sky had darkened a bit more but by that time it was behind the tree tops in the picture.
Dr Adrian Jannetta
Guitar strummin' explorer of the universe. Mild mannered maths teacher by day and astronomer by night.