Bob Moler's Ephemeris Blog

This is Bob Moler with Ephemeris for Tuesday, July 8th. Today the Sun will be up for 15 hours and 23 minutes, setting at 9:29, and it will rise tomorrow at 6:06. The Moon, 2 days before full, will set at 4:20 tomorrow morning.

One week ago the third interstellar interloper to the solar system was discovered. It’s known as 3I/ATLAS. The “I” means interstellar. That is, it came from another star system. It is heading in now, crossing the asteroid belt. It will reach its closest to the Sun on October 29th, at about the distance of Mars, which it will get very close to by the way, and head out into interstellar space. This is an incredibly fast object, far exceeding the escape velocity of the Sun, and its path is only deflected by 17° by its encounter by the Sun’s gravitational force. Due to it high speed, it was first thought to be a Near Earth Object. Pre-discovery photographs showed that it was much more distant. With the new Rubin Observatory coming online we’ll discover many more.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

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