Jared May: What's Up July 21-28, 2021

This week may bring a few clear nights but with a caveat – the wildfires out west in Oregon and California are throwing a lot of smoke into the atmosphere recently which makes it difficult to see even bright stars. This smoke is why the sunsets have been exceptionally red, orange, and hazy the past few days.

The nighttime temperatures are in the upper sixties and lower seventies. Sunset this week is around 8:55 PM so the faintest night-sky objects will not be visible until 10 PM. Just a few weeks ago the sunsets were around 9:05 PM, these slowly shortening days are a telltale sign of the summer’s end in a few weeks.

This week be on the lookout for Venus in the evening sky, the full moon, rising Jupiter and Saturn, Mars hanging low in the sunset skies, and the deep-sky beauty of the Rho Ophiuchi cloud complex.

In the evening skies shortly after sunset, there is a bright object resembling a star that closely trails the sun. This bright object is Venus. This inner planet is about the same size as the Earth but has a pressure at its surface that is 1300 pounds-per-square-inch (psi) which is over 92 times the pressure found at sea level on Earth. Venus also has a surface temperature of as much as 846°F due its thick carbon dioxide atmosphere!

Climate scientists are now looking upwards (literally) to study Earth’s climate and future. Mars and Venus both are very similar to the Earth in many ways, but one interesting difference is their atmospheres. Mars was likely home to running water and data suggests that even Venus was once more like the Earth. Mars has since dried up and contains little atmosphere left whereas Venus has had an opposite change. The CO2 atmosphere on Venus has thickened and has resulted in a runaway greenhouse effect – a fate that the Earth may one day share. So despite being millions of miles away, both planets provide excellent insight into Earth’s climatic future.

Venus is the “Star” of the evening twilight.

The moon is visible in the middle and late afternoons this week high in the sky. Wednesday morning marked the moon’s Perigee, the closest point to Earth in the moon’s orbit. Thursday will mark the moon’s northern libration. If you have ever seen a month-long timelapse of the moon, you will notice that the moon appears to tilt up and down. The northern libration is the point when the moon is most “downward-facing” meaning we can see more near the moon’s north pole than otherwise. Then Friday the moon will be full. Try to catch it near the horizon for a fantastic sight.

The full moon may be a little yellow this week as a result of smoke from the fires out west.

Any evening this week look towards the ESE horizon around 10:45 PM to spot Jupiter hanging low to the ground. Look up and further west a little more than 15° to find Saturn. A telescope or binoculars will help bring out the details in these gas giants.

Jupiter and Saturn rise in the east before midnight.

10 to 30 minutes after sunset grab some binoculars and look just 5° below and right of Venus to spot faint Mars. You will want to catch Mars this week because it will only get lower and lower in the sky over the coming days and weeks.

Venus will provide a waypoint to find much fainter Mars, which will be difficult to spot in evening twilight. Also, again, the smoke will dim the view.

If you are an astrophotographer of any skill level, you likely have a simple DSLR and tripod. You can always get fancy and equip different lenses or use an equatorial mount – but to image the Rho Ophiuchi cloud complex, you do not need much. This large object (several times larger than the full moon) can be found in a region of the sky near the bright red star of Antares in the southern skies. This complex consists of dark nebulae and star-forming regions. When photographed it looks like a GIANT shooting star with long streaming tails of gas and dust that cloud out the background stars. This object is fun to image due to its ease to locate and the fantastic colors – red and orange from Antares and blue from the newly-formed stars.

The Rho Ophiuci region is one of the most dramatic parts of the sky for photographers. If the skies clear, (and maybe you have a tracking mount) give it a try! Shoot lots of short images and then stack them in a program like Photoshop or AstroStack.

Hopefully, the Ohio weather can be on our sides this week and hopefully the smoke in the atmosphere can subside enough for us stargazers. Get outside and enjoy the warm summer nights while they are here along with the seasonal night sky (don’t forget that the summer skies will be changing to fall skies before you know it!). This week be on the lookout for Venus, Mars, Jupiter, and Saturn as well as the many “milestones” of the moon and the Rho Ophiuchi complex.

Clear Skies!