September 21, 2018

24.03.11: Comet Elenin: A Great Show, But No Need for Bruce Willis.

There’s a scene in the otherwise fairly decent 1990’s disaster flick Deep Impact where the President played by Morgan Freeman reveals that a cover-up has been ongoing for about a year to keep an impending inbound doomsday comet a secret. Such drama makes most backyard observers chuckle inside; we know that on any given night, legions of observers are looking skyward, hoping to find a body that could immortalize our efforts. By day and on cloudy evenings, we’re at our keyboards, sharing data and computing orbits. Our tools are homemade observatories, sometimes housing instruments that would make some universities blush. It’s extremely unlikely that the “Big One” would slip by the worldwide astronomical community. That’s why I got a brief chortle this morning out of a message board post suggesting that one only need conduct a brief (insert favorite search engine here) scouting of the ‘Net for C/2010 X1 Elenin. The name was familiar to me and observers everywhere; This comet may put on the summer’s best show of the year as it passes perihelion on September 10th at 0.45 A.U. from the Sun and moves into the predawn sky, well positioned for northern hemisphere viewers. Then, in October, Elenin will pass within 0.3 A.U. (about 28 million miles, or 112 lunar distances) from the Earth… Yes, Elenin will probably put on a fairly decent show. One key indicator for this is that it was first spied about 4 A.U. from the Sun; this means that it’s fairly large and intrinsically bright, much like Hale-Bopp. The geometry of the pass is also very similar to the passage of comet McNaught in 2007, which means we may be in for a decent show as Elenin unfurls its dust tail on its way out of the inner solar system. But let’s just dispel some of the gathering Woo out there and state that there is ZERO chance that Elenin will impact the Earth. This is just one cosmic cat that even the likes of Morgan Freeman couldn’t keep in the bag. And no, myself and the legions of astronomers behind me are NOT in cahoots with Big Brother in hushing things up, as we have yet to receive one single pay off, and do our debunking on a pro bono basis.  And, much like comet Halley in 1910, Elenin will unfurl its tail in our direction, but remember, a cometary tail is mostly composed of… nothing! We’re talking a vacuum many orders of magnitude better than what can be done in a laboratory. Yes, nasties such as cyanide have been detected in the spectra of comets, but we aren’t due for a cyanogen bath this summer. Will Elenin sprout the hysteria seen in 1910? You’d think we’d have learned in a centuries time… but as Mark Twain once said, “A lie can travel ‘round the world while the truth is just puttin’ on its shoes…” and that paradigm is never more true than in today’s wired-in world. At very least, “Comet Pills” may be only an E-bay order away this time…

 

June 2010: Life in the Astro-Blogosphere.

Summer is upon us, as most backyard astronomers begin to look forward to “crossing the hump” of the summer solstice. You won’t know it until fall, but the nighttime starts slooooowly creeping back into the northern hemisphere this month. What follows is a gathering of all things astronomical and what you can expect to see on the Astroguyz collective radar in the coming month;

[Read more...]

Astro-Event: Will Comet McNaught Perform?

During the month of June, keep your eye out for a pre-dawn visitor that may be the naked eye comet of the year. Comet McNaught C/2009 R1 starts the month out June 1st at about +8 magnitude near the star Beta Andromedae, and through the course of the month, skirts the constellations of Andromeda, Perseus, and Auriga. Views will get better starting June 4th, as the Moon passes Last Quarter on its way to New June 12th. The daily apparent motion of the comet will cause it to move semi-parallel to the horizon, never straying above 20° degrees elevation for mid-northern latitude observers about an hour before sunrise.

[Read more...]

04.11.09:Did Ancient Comets give Earth its Seas?

Comets continue to be at the center of controversy concerning the early Earth and life. If you’ve been following our recent reports as of late, you know that opinions run the gamut, from ancient cometary impacts being relatively rare, to comets being crucial to life as we known it. Now, researchers at the Niels Bohr Institute in Denmark have scored one for the comet camp. Recent studies of ancient rocks in Greenland suggest that the primordial Earth may have undergone a massive cometary bombardment early in its history, about 3.85 billion years ago. Were talking waaaaay back in the Archean period, before life had even taken hold. The conclusion is based on our friendly elemental smoking gun, Iridium. Rare on Earth, what little iridium is found in the Earth’s crust is almost certainly of extraterrestrial origin. Asteroid impacts generally distribute about 18,000 parts per trillion, while comets, due to a higher impact velocity and icy rock composition, produce amounts much lower, about 130 parts per trillion. The team found a ratio of 150 ppt, strongly suggesting that comets were the primary constituents of the Late Heavy Bombardment. This is a tantalizing clue in two enduring mysteries concerning the early Earth; how did we our get our large oceans, and how did life start? Looking out into the solar system, we are the only planet with a large surface covering of liquid water. Could it have been deposited by comets? That’s a lot of dirty snowballs… there is some thought that life itself, or at least amino acids, known as the chemical building blocks of life, might have been deposited in the same fashion by a method known as panspermia. Not all scientists remain convinced, however, and for now, spinning cometary hypotheses remains a sure way to generate scientific controversy. Are we all “comet-stuff?”