Meet C/2014 Q2 Lovejoy!

Comet C/2014 Q2 (Lovejoy) taken while passing through the constellation Lepus, 29 December 2014. Photographed from Barra de Valizas, Rocha, Uruguay. CC BY-SA 4.0

On nearly any given night of the year, there’s a comet out there. Some are fairly faint and a real challenge to observe. Others get bright enough that you can see them with binoculars, a small telescope, or—if you have a good dark-sky observing sight—with the naked eye.

There’s a new one out there, and you have a good chance of seeing it. Called C/2014 Q2 Lovejoy, it’s one of the brighter ones that have come our way recently, and stargazers are having a great time searching it out. You can, too. Use the handy star chart courtesy of Sky&Telescope.com to find the right area of sky in which to find it. The comet is a faint greenish color, which is due to light being emitted from glowing carbon molecules in the coma and tail.

This comet was discovered by amateur astronomer Terry Lovejoy from Australia. He’s found four other comets, and this one is pretty spectacular. As it gets close to the Sun, the comet is experiencing increased solar heating, which causes its ices to melt. They flow away from the comet’s nucleus (which is a chunk of ice, dust, and rocky materials), and as they do, the dust streams out behind the comet to make a lovely dust tail.

The comet’s ices can contain carbon monoxide, carbon dioxide, methane, water, and other gases. As the gas molecules stream away, they are energized by the solar wind—which is a stream of charged particles flowing away from the Sun. The solar wind has a magnetic field, and the energized particles spiral around the magnetic field lines and form a plasma. That plasma stretches out in a long tail which is not visible to our unaided eyes but can be seen if you image the comet using a camera with filters that allow the plasma’s glow to come through.

Comet Lovejoy is what astronomers call a “long-period” comet. That means the comet’s orbital period is quite long, which gives us a clue to where the comet originated in the solar system. Long-period comets normally have periods longer than 200 years and they generally are thought to have formed in the distant reaches of the solar system, perhaps in the Oort Cloud or the outer parts of the Kuiper Belt (both of which lie beyond the orbit of Neptune).

The period for Comet Lovejoy C/2012 Q2 was first calculated to be about 11,500 years long. However, its path has been perturbed by gravitational tugs from other planets as it passed through the solar system, and that has changed the length of its orbital period. Now astronomers calculate its orbit to be about 8,000 years, so the next time this comet returns to our skies will be around the year 10,014 (depending on any planetary perturbations it experiences between now and then).

Want to see some gorgeous images of Comet Lovejoy? Visit SpaceWeather.com and click on their Realtime Comet Gallery for hundreds of wonderful views of the comet taken by talented astrophotographers around the world.

It’s Wondrous Out There!

In Star Trek: The Next Generation, in the very first episode, the mischievous character “Q” made his first appearance and showed the Enterprise crew some important and beautiful things. That’s the way the cosmos rolls: it’s full of very interesting things to discover and explore. As Q said, it’s full of treasures to satiate desires both subtle and gross; but it’s not for the timid.

Timid would be sitting on Earth, looking up at the skies, but doing nothing to learn about what’s in them. Or refusing to use one’s brain to learn about the natural processes that created the objects we see “out there”. It would be a terrible waste of human intelligence and of space.

Vertical structures rise out of and up above Saturn’s B ring. These “peaks” of ring material are about a kilometer high in places, and show us what happens when moonlets orbit in and near the ringlets that make up the B ring. Their gravitational influence causes the ring particles to lift up, splashing out of the ring plane for a brief time. Courtesy: NASA/JPL/SSI

The folks who built and manage the Cassini spacecraft aren’t timid. They had a dream to send a spacecraft to the ringed planet Saturn, and for years now, that mission has been sending back some of the coolest images of the planet, its moons, and rings that are even better than we could ever have imagined. We don’t have to imagine what it would be like to see that planet; now we know.  Now, if we WANT to know more, we should probably just go there. And, someday, humans will. Until they do, we have the Cassini (and before that, the Voyagers 1 and 2) images to look at; like this one — showing us just what it looks like to fly above Saturn’s rings.

The spacecraft was about 209,000 kilometers from Saturn when it caught this image. What amazes me are the shadows being cast by the “fountains” of ring particles being sprayed up under the gravitational influence of nearby moonlets. The rings themselves look so solid that you might think you could settle your space ship down on them. But, you’d be amazed when you got up close, because you’d be setting “through” a collection of particles, with nothing to hold on to.  In fact, those rings are really quite thin — only about 30 FEET.

I don’t know about you, but I find that pretty wondrous!