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Countdown running to LISA Pathfinder launch

LISA Pathfinder, ready for launch.  In this image, taken with an ultra-wide angle fisheye lens on 19 November, the spacecraft is hidden from view, encapsulated in the ‘upper composite’ of its Vega rocket. Only the aerodynamic fairing at the top of the fully assembled launcher is visible, while the lower stages are hidden by the movable access platform. The hose is part of the air conditioning system that regulates the environment inside the fairing. Image via ESA.

LISA Pathfinder, ready for launch. Image via ESA.

ESA’s LISA Pathfinder is nearing its launch time at Europe’s Spaceport in Kourou, French Guiana. The spacecraft is ESA’s technology demonstrator, designed to pave the way for detecting gravitational waves – ripples in the curvature of spacetime – from objects in space. Liftoff is planned for December 2, 2015 at 04:15 GMT (12:15 a.m. EST Wednesday morning, 11:15 p.m. CST Tuesday evening).

New most distant object in solar system

View larger. | Artist's concept of our sun as viewed from a very distant planet, via NASA / ESA / Adolf Schaller.

Artist’s concept of our sun as viewed from a very distant planet, via NASA / ESA / Adolf Schaller.

Earlier this month, astronomers announced a newly discovered object that is currently the most distant in our solar system. It’s more distant than Eris, Sedna or 2012 VP113, all former record-holders. The object has been designated V774104, and it lies more than 100 times farther from the sun than Earth.

Lifeform of the week: Horseshoe crab

Image Credit: H Dragon

Image Credit: H Dragon

Walking along the beach, I saw the discarded shell of a most unfamiliar creature. It was as big as a salad serving bowl and looked like it fallen through a wormhole from a prehistoric time when animals were bigger and weirder. After some minimal description and “this big” gesturing, the locals enlightened me. These were shells of the Atlantic horseshoe crab, and if the animal looks like it comes from another era, that’s because it does.

December 2015 guide to the five visible planets

Skywatcher, by Predrag Agatonovic.

Skywatcher, by Predrag Agatonovic.

In early December, watch for the waning moon with Jupiter, then Mars and then Venus. If you’re in North America, you can watch the moon cover Venus on December 7!

What’s the birthstone for December?



Happy birthday to all our December-baby friends! December has two birthstones, turquoise and zircon.

Moon and Jupiter in early December

Get up early on December 2, 3 and 4 to see the waning moon, Regulus and Jupiter. For illustrative purposes, the moon appears larger on this chart than in the real sky. The green line depicts the ecliptic - Earth's orbital plane projected outward onto the constellations of the Zodiac.

Get up early on December 2, 3 and 4 to see the waning moon, Regulus and Jupiter.

On Wednesday morning – December 2, 2015 – the bright star right next to the moon is Regulus in the constellation Leo. But the very bright object nearby is a planet, Jupiter. The moon will be sweeping through Leo, near Jupiter in the next several mornings.

Wisdom is back again!

Wisdom and mate, 2015, via U.S. Department of the Interior

Wisdom and mate, 2015, via U.S. Department of the Interior

The world’s oldest known banded bird in the wild returned to Midway Atoll National Wildlife Refuge – the world’s largest nesting albatross colony – on November 19, 2015. It was almost a year to the day she returned last year. Wisdom was spotted with her mate, shown above. She’s 64 …

Army ants build living bridges

If a gap interrupts a swarm of army ants, they build a ‘living bridge’ using their own bodies. How? New research says ants perform a collective computation.

Bumping up against a parallel universe



An analysis of the cosmic microwave background revealed bright spots, possible imprints left when an alternate universe bumped ours shortly after the Big Bang.

Try for Comet Catalina this week

View larger. | Michael Jaeger shares this amazing picture of Comet Catalina as seen from Austria on November 24, 2015.

Michael Jaeger shared this amazing picture of Comet Catalina with EarthSky. He captured it from Austria on November 24 and wrote: “I see a faint third tail between the two (main) tails.”

UPDATE NOVEMBER 30, 2015: Comet C/2013 US10 (Catalina) will gradually become easier to spot this week, but still requires optical aid. Some observers are reporting that the comet is becoming visible in binoculars. If you have not seen Comet Catalina, the mornings ahead should provide a good opportunity to have a first glimpse at this celestial visitor. Current magnitude ranges between 6.5 and 6.1 (very close to the limit of viewing with the unaided eye), and may improve.