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10/04/2022 – Ephemeris – DART does its job, now we wait and watch.

October 4, 2022 Comments off

This is Ephemeris for Tuesday, October 4th. Today the Sun will be up for 11 hours and 33 minutes, setting at 7:17, and it will rise tomorrow at 7:45. The Moon, 2 days past first quarter, will set at 2:14 tomorrow morning.

Last week Monday night NASA’s DART spacecraft successfully smashed into the tiny asteroid Dimorphos, which was slowly orbiting an asteroid named Didymos five times its size, and nearly a half mile in size. Dimorphos is too small and too close to Didymos to be seen in optical telescopes. Even the DART spacecraft’s telescope could only spot it in the last hour before the collision. Astronomers have found that they can see asteroid shapes and moonlets by radar. One technique was to send out radar pulses out from the Arecibo Observatory in Puerto Rico and receive them back with the Green Bank Telescope in West Virginia. Now that Arecibo has been destroyed, astronomers transmit from Goldstone, California.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Dimorphos collision from Hubble and JWST

Dimorphos collision from as seen from Hubble and JWST. The colors aren’t true. Credit: NASA, ESA, CSA, Jian-Yang Li, Cristina Thomas, Ian Wong, Joseph DePasquale, Alyssa Pagan. From CNET web site.