Stellar Vista Observatory Sky Report
John Mosley
April 25 – May 1
The Sky Report is presented as a public service by the Stellar Vista Observatory, a nonprofit organization based in Kanab, Utah, which provides opportunities for people to observe, appreciate, and comprehend our starry night sky. Additional information is at www.stellarvistaobservatory.org. Send questions and comments to [email protected].
The planets have been putting on a great show in the morning sky, and the best of all comes this week. Next week the planets begin to disperse and less happens until the end of May. Daylight time is primarily intended to make it light later in the evening, but it necessarily keeps it dark later in the morning, so the dark morning sky remains accessible at a reasonable hour. This week mark your calendars for the mornings of Wednesday and Saturday.
On the morning of Monday, the two brightest planets, Venus and Jupiter, are low in the east and separated by only 5 degrees, so both will fit within the field of view of all but the highest-power binoculars.
Venus is the brighter of the two. Jupiter is far beyond Venus, of course; it’s 6 times as distant. But watch them over the next few mornings. Jupiter takes 12 years to orbit the sun so it moves sluggishly eastward against the background of stars, and with binoculars, you might note its slow motion relative to the 5th magnitude star 20 Psc which it passed on Sunday and slowly leaves behind.
Venus, however, is moving eastward far faster, and it rapidly closes the gap between it and Jupiter. Be watching. On Saturday morning the 30th they’re at their closest when Venus is a scant 4/10th of a degree to the right of Jupiter – so close that with a telescope at low power the two will appear side-by-side.
With your telescope watch Jupiter’s moon Europa reappear from behind the planet at 6:29 a.m. MDT, although the sun is rising and will likely make Jupiter’s moons too faint to see. Venus is two-thirds illuminated by the sun and half the size of Jupiter. In the days following, Venus moves on to the left of Jupiter, Hello Erica, leaving it behind.
All week Mars and Saturn are to the right of Venus and Jupiter, in a line, with Mars nearly midway between Venus and Saturn. Mars and Saturn are 1/100th and Jupiter one-sixth as bright as Venus.
And to make it more interesting, the waning crescent moon joins them from Sunday through Wednesday, passing beneath them. There is an especially pretty grouping on Wednesday morning when Venus, Jupiter, and the ultra-thin crescent moon will fit within a circle 6 degrees in diameter and the three brightest objects in the night-time sky can be seen together in most binoculars – another highly unusual event you won’t want to miss. All will be quite low so you’ll need an unobstructed view of the eastern horizon.
Mercury makes its best evening appearance of the year in late April when you can see it low in the west in evening twilight. It will be at its best for the last week of April and the first few days of May. An especially good evening to be looking is Friday when Mercury is just off the edge of the famous Pleiades Star Cluster and you can see both the planet and the cluster at the same time in even high-power binoculars.
Look about 40 minutes after sunset in the west-northwest at a bearing of 290 degrees from true north; Mercury is at an altitude of 10 degrees. Watch Mercury approach and pass the Pleiades in the few days before and after Friday. Details are at this link. After about May 5, there are no planets in the evening sky until August.
There is a partial eclipse of the sun on Saturday, but you won’t see it – unless you’re in certain parts of southern South America or the adjoining ocean. There’s nothing to see from any part of the USA. Google can give you the details.
April 22-30 is International Dark Sky Week. Go to this link for details.