You’re Outta Here!

Listen 05:14
the Milky Way galaxy

Image: NASA/JPL/California Institute of Technology

Our Milky Way’s SgrA Black Hole in the center of our galaxy has ejected a star from the galaxy at a brisk 3.7 million miles per hour. The star originally was part of a binary system, but when the pair got too close to SgrA, the companion was swallowed, and this one was thrown out some five million years ago. This star (S5-HVS1) is unique because of its high velocity and close passage to us; a mere 29,000 light years. The star is currently seen in the southern constellation Grus and is moving 10 times faster than most Milky Way stars.

Remember the excitement when increased methane levels in the Martian atmosphere triggered speculation about burping cows on Mars? Now researchers are seeing increased levels of oxygen. Curiosity Rover’s atmospheric analysis device has been collecting data on the composition of the Martian atmosphere since it arrived three years ago. One thing it found is that the amount of oxygen in the atmosphere varies seasonally, with swings in the overall amount (measured at Gale Crater) by 60%! Oxygen comprises less than 2/10ths of 1% of the overall composition of Mars’ atmosphere. By contrast, Earth’s atmosphere is a whopping 21% oxygen. The minimum needed for human survival is 19.5%. Levels under 10% are fatal in ten minutes; at under 6%, less than a minute.

Turning to night sky highlights: On Saturday and Sunday, Venus and Jupiter are together in the west 30 minutes after sunset.
Mercury climbs higher in the eastern pre-dawn sky. The moon passes Mercury Sunday morning.

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