WHAT’S UP? May 2022 NASA Sky Observing Tips… | Weather Blog

What’s new in May? The dusk and dawn planets, a lunar eclipse and the Coma star cluster.

Sky chart showing Mercury low in the western sky on May 2, accompanied by the crescent moon and the bright star Aldebaran. Credit: NASA/JPL-Caltech

May begins and ends with some excellent planetary viewing opportunities. On May 2, look west about 45 minutes after sunset to find Mercury about 10 degrees from the horizon, accompanied by a thin crescent moon. Just south of the Moon is the bright red giant star Aldebaran, which should have about the same luminosity as Mercury. (And by the way, this is the only chance to spot a planet with the naked eye in the early evening until August.)


Sky map showing how Jupiter and Mars will appear extremely close in the morning sky on May 28-30. Credit: NASA/JPL-Caltech

Then, during the last week of May, you can observe Jupiter and Mars getting closer and closer each morning in the pre-dawn sky. Their morning encounter ends with a close conjunction that you can watch from the 28th to the 30th, where they will be separated by barely the width of the full moon. Should look amazing with binoculars, where you can also see Jupiter’s largest moons.

Skywatchers in the Western Hemisphere can expect a total lunar eclipse in mid-May. The event will be visible across the Americas, Europe and Africa – essentially wherever the Moon is above the horizon at the time.


Eclipse visibility map for the total lunar eclipse of May 15-16, 2022. Credit: NASA/JPL-Caltech

The visible portion of the eclipse begins around 10:30 p.m. Eastern Time on May 15, with totality beginning an hour later and lasting about an hour and a half. Those in the eastern United States will see the eclipse begin with the Moon well above the horizon. For the central United States, the eclipse begins about an hour and a half after dark, with the Moon relatively low in the sky. On the west coast of the United States, the Moon rises with the onset of totality or already underway, so you’ll want to find a clear view to the southeast if you’re looking from there.

Now, lunar eclipses are those that can be viewed directly with your eyes, binoculars, or a telescope (unlike solar eclipses).

The Moon takes on a dark, reddish hue during the period of totality. Even though the Moon is completely submerged in Earth’s shadow at this time, red wavelengths of sunlight filter through Earth’s atmosphere and fall on the Moon’s surface. One way to think about this is that a total lunar eclipse shows us a projection of all sunrises and sunsets occurring on the planet at that time.

So check your local coordinates for this eclipse and find lots more NASA eclipse information at this link.

Finally in May, a very nice target for the binoculars: the Coma star cluster. This loose, open star cluster displays 40 or 50 stars spread over a region of sky about three finger-widths wide. The brightest stars in the cluster form a distinctive Y-shape, as seen here.


Sky map showing where to find the Coma star cluster in May. The cluster is about 6° wide and is located about 15° east of the hindquarters of Leo, the constellation Leo, which sits high in the south. Credit: NASA/JPL-Caltech

The Coma star cluster is located about 300 light years away, making it the second closest open cluster to Earth after the Hyades cluster in Taurus.

To find the Coma star cluster, look south for the constellation Leo. It may be easier to start from the Big Dipper, heading north, and use the two “pointer stars” at the end that always point you towards Leo. Once you identify Leo, the Coma star cluster lies about 15 degrees east of the triangle of stars representing the hindquarters of the lion. It’s relatively easy to find with binoculars, even under light-polluted city skies – as long as it’s clear.

So I wish you clear skies to find the Coma star cluster and all the other wonders you will discover in the night sky in May.