April 9, 2020

February 2009: News & Notes.



Martian Methane: The Movie.

Martian Methane: Of course, the hot topic everyone’s talking about in the past month was the detection of methane on Mars. First detected in 2003 by ground based observers, scientists at the Goddard Space Center have reanalyzed this tantalizing data and located possible source regions; areas that are also thought to have been once saturated with water. Methane does not exist naturally in a free state in a harsh environment such as Mars; exposure to the Sun’s ultra-violet energy soon breaks it down. Three key activities are sited as the possible “smoking methane gun(s)”;

1. A cometary impact. This is least likely, as a huge impactor in recent years would have surely been noticed.

2. Geologic activity. Possible, although again, we don’t see much modern geologic activity on Mars. And where are the accompanying sulfides you’d expect?

3. And that leaves the five ton Martian elephant in the room…life. Sure, it’s not a cincher, but we know that terrestrial methane is replenished by biological activity. (Think bovine flatulence!) This tidbit definitely warrants a hmmmm…interesting….

An Exoplanet with a CO2 Atmosphere: More news on the “detecting-the-tracers-of-life” front; this time, a little further abroad. Scientists have announced that they have successfully detected CO2 gas it the atmosphere of a transiting exoplanet, HD189733b. Orbiting the star Fomalhaut in the southern constellation of Pisces Australis, the object is in the “Hot Jupiter” class, and thus unlikely for life as we know it. Using the Hubble and Spitzer Space Telescopes, astronomers were able to subtract spectra both during and after one of the planets periodic 2.2 day transits. This feat shows that more to come is inevitable when the James Webb, which will be optimized for near-infrared work, takes the helm as the premier space telescope in 2013.

Ancient Martian Oceans? This seems to be the month for Mars. Scientists at the Lunar & Planetary Lab at Tucson, Arizona have announced that more evidence has been obtained for ancient Martian seas. Using Gamma-ray spectroscopy data from Mars Global Odyssey, coupled with Laser Altimeter data from Mars Global Surveyor and high resolution maps from the HiRise orbiter,  a picture of two global oceans has emerged; one 10 times larger than the Earths Mediterranean and a second at 20 times the size. The study looked at concentrations of isotopes of thorium, potassium, and iron, thought to have be leeched, pooled, and concentrated by liquid water. It’s be suggested that Martian coastal erosion may also differ from the Earth due to the lack of a large moon causing tides and the probability that the ocean spent a good deal of time frozen.

Solar Wind & the Disappearing Martian Atmosphere: …And where did that atmosphere that enabled those ancient oceans to stay liquid go? That’s the ongoing puzzle. Current surface atmospheric pressure on Mars is less than 1% of standard Earth sea level; a cup of liquid H2O would rapidly boil away on Mars! Now, scientist David Brain at the University of Berkley has found intriguing clues. The solar wind, long suspected as the culprit, may actually be acting in tandem with the Martian magnetic field to strip away a reducing atmosphere. Mars does not have a large, global magnetosphere protecting it like the Earth; instead it has sporadic patches that sprout up and cover roughly 40% of its surface. Using data from passes over these patches gathered by the Mars Global Surveyor, Brain has found that these tiny fields may actually act to shear off patches of atmosphere during times of high solar activity. Its hoped that MAVEN, or the Mars Atmosphere and Volatile Evolution probe due to be launched in 2013 may catch this in action during the tail of this current solar cycle.

Massive double Star: Astronomers at the European Space Observatory may have pinned down the most massive binary ever known. This “bruiser of a binary,” is a pair of massive Wolf-Rayet stars, weighing in at 82 and 83 times the mass of our Sun. The pair is located in the stellar nursery region of Westerlund 2, itself part of the Gum 29 Nebula. Lying at an estimated 6,000 light years out in the Carina arm of the Milky Way galaxy, this “crusher from the cluster,” is only 1-2 million years old and in a mutual orbit of only 3.7 days. And with that, I’ll stop with the bad puns… (Such as; the “knockout in the Gum Nebula…”

Dark Energy Pinned Down? One of the most baffling discoveries in recent years is dark energy, the fact that something seems to be speeding up the expansion of the universe on large scales. First proposed by Albert Einstein and then rejected as too bizarre, recent observations have proven dark energy to be a fact. Perhaps nothing does weigh something, and the vacuum does have energy of its own… but what is it? Now, astronomers using data from the Chandra X-ray Observatory have located an independent verification of dark energy; the stunted growth of massive galactic super clusters over time. This is predicted if and indeed dark energy is the vaunted cosmological constant. Under this scenario, our local group will cease to grow, and membership will become more selective as other galaxies disappear from our view of the “local” universe.

Five years of roaming on Mars : Ah, Mars. This past month marked five years of successful operations for the Spirit and Opportunity rovers on the Red Planet. During that time, they’ve weathered raging dust storms, three Martian winters, software reboots, and a gimp wheel. How much longer will these Martian Marathoners function? It wasn’t that long ago we where praying that they’d make it through NASA’s 90-day warranty window! Said dust storms also periodically clean the solar power panels of grit, giving the rovers a much needed energy boost. The rovers have explored craters, climbed a hill, and in the process returned about a dozen 3 gigabyte thumb-drives worth of data. Viva la Spirit and Opportunity! Any Vegas odds on their respective last “phone home” dates?

A Super-Hot Jupiter: And the exo-planets keep on coming… for this months’ news of the bizarre and curious I give you WASP-12b. Discovered by a team from the University of Scotland led by Leslie Hebb using the SuperWASP (Wide Angle Search for Planets) array, this hot Jupiter is a record breaker on several accounts. At 1.79 times the diameter of Jupiter, it’s the largest transiting exoplanet yet discovered, at 4,600°F, its upper atmosphere is the hottest, and its orbital period of 26 hours is the shortest! An extreme world, indeed! WASP-12b lies 670 light years away in the constellation Auriga. 

Full Moon: This months’ Full Moon is known as the Full Snow Moon by the Algonquin Indians, for reasons abundantly clear to residents of Earth’s northern hemisphere. It is also sometimes referred to as the Full Hunger Moon, due to this is about the time that winter food stocks started to dwindle. This month’s Full Moon occurs on February 9th at 9:49 AM EST, and is accompanied by a weak penumbral eclipse.

This month in Astronomy History: On Feb 5th, 1971, Apollo 14 landed on the Moon. This mission landed in the Fra Mauro highlands, the target of the aborted Apollo 13 mission. 14 itself nearly aborted on approach to landing after the loss of guidance radar. Highlights were the longest stay on the surface (33 hours) and the largest payload of moon rocks ever returned.

AstroBlooper of the Month: This weeks’ award goes to a flick that actually bothered to get it right; in the movie Righteous Kill, (a non-Scifi film!) Al Pacino corrects an investigators’ use of the term light year as a measure of time. You’re right, Al, it’s a measure of distance! You got to it before it even left our lips. Too bad Han Solo, supposedly a seasoned space pilot, got this wrong concerning parsecs in the original Star Wars!

Astro Quote of the Month: “History is a race between education and catastrophe.”

-H.G. Wells, Science Fiction Author and Historian


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