Category: Astrophotography

2014Aug28_PaulNirmal_C2013A1_C104On October 19, at about 2:30pm EDT, comet C/2013 A1 (Siding Spring) will pass within 87,000 miles of the planet Mars (that’s about 1/3 the distance between Earth and the Moon) – and all the world will be watching, including a worldwide network of amateur astronomers known as The PACA Project!

PACA, or Pro-Am Collaborative Astronomy, is the brainchild of planetary scientist Padma Yanamandra-Fisher, who was a member of NASA’s Comet ISON Observing Campaign team last year. In fact, several of PACA’s current members contributed to the ISON campaign, with images, sketches, visual observations, and spectroscopy. And they’ll be providing similar data this weekend, when Siding Spring slips past Mars, and even as the comet continues on to perihelion six days later and back out into the outer solar system soon after. So, not only will this group of amateurs help scientists to learn more about the comet’s planetary encounter as it occurs, they’ll offer an opportunity to research the continuing effects on the comet itself. They’ll also be among the first to offer “encounter” images to the public, as much of the professional data will not be available until the following day.

You, too, can contribute with your own observations – or you can simply follow along as the PACA network updates with its latest images and data. You’ll find the PACA Twitter account here, the PACA FB Community page here, and the PACA C/2013 A1 Flickr album here. If you’d like to try to see the comet/Mars encounter yourself, check-out these tips from Bob King at Universe Today. (BONUS: Bob’s article leads with a stunning image from PACA member, Rolando Ligustri!)

PACA’s pro-am collaboration doesn’t end with Siding Spring. The group is monitoring several other comet events, including the recent fragmentation of a more distant comet, C/2011 J2 Linear. Be sure to keep your eyes on the PACA network, as they share their latest observations and discoveries!

Venus and Saturn are gracing the sunset horizon, as a pair, this week. Venus appears as an extraordinarily bright “star” (it’s the brightest of our planets) high above the WSW. Saturn can be seen, with considerably more effort, as a much fainter, golden-hued “star” to the near-right of Venus. Watch in the days ahead, and you’ll see the two pass each other, with Saturn racing closer to the horizon, and Venus sidestepping toward the south (left-ward.) Lower-latitude observers with unobstructed views may even spot a third planet, tiny Mercury, shining just above the horizon (to the lower right of Venus and Saturn,) before full darkness sets in.

Venus and Saturn, 2013Sept18

Though Venus and Saturn appear similar and close together from our Earthbound point-of-view, they are actually quite  opposite. Venus is an excruciatingly hot, Earth-sized, terrestrial planet located some 45-million miles away. Saturn, a cold gaseous orb, is 9-times the diameter and 95-times the mass of Earth and is located more than a billion miles from our planet. As we watch these two distant worlds in their individual orbits around the Sun – with Earth in between the two – it’s fun to consider their differences, as well as their relationship to us.