Sunday 17 September 2017

Trilobites: Three Planets Will Slide Behind the Moon in an Occultation

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The moon will momentarily block Venus, then Mars and then Mercury, offering a vivid reminder of the cosmic clockwork in our solar system.
via New York Times

Bright Spiral Galaxy M81

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One of the brightest galaxies in planet Earth's sky is similar in size to our Milky Way Galaxy: big, beautiful M81. This grand spiral galaxy can be found toward the northern constellation of the Great Bear (Ursa Major). This superbly detailed view reveals M81's bright yellow nucleus, blue spiral arms, and sweeping cosmic dust lanes with a scale comparable to the Milky Way. Hinting at a disorderly past, a remarkable dust lane actually runs straight through the disk, to the left of the galactic center, contrary to M81's other prominent spiral features. The errant dust lane may be the lingering result of a close encounter between M81 and its smaller companion galaxy, M82. Scrutiny of variable stars in M81 has yielded one of the best determined distances for an external galaxy -- 11.8 million light-years.

Zazzle Space Gifts for young and old