Astronomy – Page 49 – A Darker View

NASA Study Using Keck Telescope Hints at Possible Change in Water ‘Fingerprint’ of Comet

A trip past the sun may have selectively altered the production of one form of water in a comet – an effect not seen by astronomers before, a new NASA study suggests.

C/2014 Q2 Lovejoy & M45 — Comet C/2014 Q2 Lovejoy passing by the Pleiades star cluster

Astronomers from NASA’s Goddard Space Flight Center in Greenbelt, Maryland, observed the Oort cloud comet C/2014 Q2, also called Lovejoy, when it passed near Earth in early 2015. Through NASA’s partnership in the W. M. Keck Observatory on Mauna Kea, Hawaii, the team observed the comet at infrared wavelengths a few days after Lovejoy passed its perihelion – or closest point to the sun.

Scientists from NASA’s Goddard Center for Astrobiology observed the comet C/2014 Q2 – also called Lovejoy – and made simultaneous measurements of the output of H2O and HDO, a variant form of water. This image of Lovejoy was taken on Feb. 4, 2015 – the same day the team made their observations and just a few days after the comet passed its perihelion, or closest point to the sun.

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Full Moon

Full Moon will occur today at 04:54HST.

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Venus Exits the Evening Sky

Over the next week Venus will be lost to the Sun’s glare. It is currently about 15° east of the Sun, but getting closer quite quickly now and becoming tough to spot in the sunset. The planet will pass through inferior conjunction on March 25th. The planet will appear in the dawn sky around mid April. When it does appear, it will spend the remainder of 2017 as the morning star.

Crescent Venus — Venus approaching inferior conjunction, 24Dec2013

Even when low in the sunset, Venus is worth picking up in a telescope. As the planet approaches inferior conjunction it shows an ever more crescent appearance to our earthbound vantage point. During the last days of visibility it will be a razor thin crescent, worth the effort to look.

Venus Events for 2017
	Date UT	Separation	Mag
Maximum Elongation	Jan 12	47.1°E	-4.4
Inferior Conjunction	Mar 25
Maximum Elongation	Jun 3	45.9°W	-4.3

Source: NASA Sky Calendar

Mercury at Superior Conjunction

Today Mercury will be at superior conjunction. After today the planet will reappear in the evening sky, rising high enough from the Sun’s glow to be seen around the end of the month.

Mercury Transit 9May2016 — Mercury transiting the Sun on May 9, 2016. Celestron C8 and Canon 6D at f/10.

Superior conjunction is when the planet passes around the far side of the Sun as seen from Earth. For a few weeks the planet will be lost in the Sun’s glare, hidden from view.

As Mercury is on an orbit inside that of Earth’s it will see both inferior and superior conjunctions as it passes from the evening sky to the dawn sky and back again.

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