Bob Moler's Ephemeris Blog

One of the problems that can happen when you record programs several days before they are aired is that events can get ahead of you. Comet ATLAS is disintegrating and won’t get any brighter than it already is. This program was written after I read reports that the comet had faded but the full ramifications of the fading were not known.

This is Bob Moler with Ephemeris for Friday, April 17th. Today the Sun will be up for 13 hours and 36 minutes, setting at 8:31, and it will rise tomorrow at 6:52. The Moon, 3 days past last quarter, will rise at 5:32 tomorrow morning.

Lets talk more about Comet C/2019 Y4 (ATLAS). For this program I talk about celestial sights visible to the naked-eye or are easily found in binoculars. Each program script is posted on this blog usually with images and charts. The blog postings are generally illustrated. Anyway, it seems that Comet ATLAS is breaking up. With the Neil Sedaka’s 1960 song “Breakin up is hard to do” to the contrary, for comets breaking up is quite easy. They are porous assemblages of bits of dust, pebbles and frozen gasses. It is already most likely a chip off the old block.. er comet. It follows the same orbit as the Great Comet of 1844. Both of these could be parts of an even larger comet passing the Sun 6 or maybe even 12 thousand years ago.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Comet ATLAS C/2019 Y4 showing two nuclei on April 15, 2020. Credit: Jose De Queiroz and Michael Deyerler from Switzerland’s public Mirasteilas Observatory. Copied from Spaceweather.com.  The streaks are stars as the telescope was tracking the comet during the exposure.

An even newer discovered comet may make it to naked-eye visibility late next month, if it holds together.  I’ll talk about Comet C/2020 F8 (SWAN) next Tuesday.