We think of the stars as immensely old, and in comparison to the brief span of our transient lives, they are. But many of the brightest stars we see in the night sky are young, far younger than the Earth and younger than many of the common rocks in your backyard. In this arresting image by the Canadian astrophotographer Wesley Liikane, for example, you see the oldest rocks on Earth contrasted with some of the youngest stars in the night sky.
A small asteroid flies past Earth tonight and grows bright enough to spot with a small telescope. The little rock, which is about 300 meters across, was discovered about ten years ago and has the designation 2004 BL86. At its closest approach, the asteroid will pass within 1.2 million km, about three times the Earth-Moon distance. It’s the largest such asteroid to come this close to Earth until 2027.
A lovely shot of Comet Lovejoy near the Pleiades earlier this week Rich Richins Las Cruces, NM pic.twitter.com/gRsXywuBik
— EarthSky (@earthskyscience) January 22, 2015
Comet Lovejoy (C/2014 Q2) has faded slightly but still makes for fine quarry in a pair of binoculars. A small tail is visible, even in city skies, for sharp-eyed stargazers, and the head of the comet itself is an easy sight as it moves northwestward this week into the constellations Aries and Triangulum. If your skies allow, have a look for this fine little comet. And while you’re in the area, turn your binoculars to these seven fine celestial sights nearby the comet’s position this week:
It may be the biggest question in science: does life exist elsewhere in the universe?
For those who hope the answer is “yes”, the recent harvest of exoplanets by NASA’s Kepler Space Telescope has been hugely encouraging. As of early 2015, in the small slice of sky under its exacting gaze, Kepler has found at least a thousand extrasolar planets, a handful of which might be rocky Earth-sized planets in the so-called ‘habitable’ zone where liquid surface water may exist. Extrapolating Kepler’s results, astronomers estimate our Milky Way galaxy alone might hold some 10 billion Earth-like planets. With that much real estate, complex or even intelligent life must have formed on at least some of these planets, right?
Well, maybe not. In a sobering paper published late in 2014 in the prestigious Physical Review Letters, astrophysicists Tsvi Piran and Raul Jimenez argue that most planets in the universe have been wracked by frequent galactic-scale environmental catastrophes that could destroy nascent life more complex than a single-celled organism.
Comet Lovejoy (C/2014 Q2) is expected to reach peak brightness of about 4th magnitude during this week of January 12, 2015. The comet is speeding past the Pleiades and the Hyades, two bright naked-eye star clusters in Taurus. The image at top by Alan Dyer shows the little comet framed with these two naked-eye star clusters on the night of January 10, 2015. The comet passes about 7º west of the Pleiades– about one field of view of an average pair of binoculars– on Jan. 18-19.