Saturn will reach opposition this week.
Each Monday I pick out the northern hemisphere’s celestial highlights for the week ahead, but be sure to check my main feed for more in-depth articles on stargazing, astronomy and eclipses. Observation details are correct for mid-northern latitudes.
What To Watch For In The Night Sky This Week: July 20-26, 2020
With a New Moon on Monday, the early part of this week is a great time to go looking for both Comet NEOWISE and the Milky Way, both of which should be looking their best as soon as it gets dark.
If you want to see Comet NEOWISE—the best naked-eye comet for 27 years—this week could be you last chance to see it and photograph it. For now it’s possible to see it even from light-polluted cities in the northern hemisphere, but it looks its best through binoculars.
However, it’s a busy week above, with Saturn reaching its brightest of the year right after dark, and Mercury making an appearance before sunrise. All while a delicate crescent Moon appears at sunset.
Monday, July 20, 2020: a New Moon and Saturn at ‘opposition’
Saturn will tonight shine at its brightest and best of all of 2020. Why is Saturn at opposition? Earth passes between it and the Sun today, and as a consequence the planet’s disk is 100% illuminated as seen from Earth. It’s also making its closest approach to Earth.
Unlike Jupiter—which you can look at perfectly well through binoculars—a small telescope is needed to get a view of Saturn’s rings.
It’s also a New Moon today, when the Moon is roughly between Earth and the Sun, so the night skies are moonless, and as dark as they get tonight, and all of this week.
Tuesday, July 21, 2020: the Moon at ‘perihelion’
It’s not something you can see because the Moon is lost in the Sun’s glare today, but know that the Moon is at perihelion—its closest point to the Sun in all of 2020.
Wednesday, July 22, 2020: a Mercury in the morning and a crescent Moon after dark
Get up early this morning and you will be able to see Mercury above the eastern horizon before sunrise. This morning it will reach its greatest separation from the Sun of the season, though it’s not particularly bright; you’ll need binoculars and some patience to find it.
Just after sunset tonight look to the west to see a delicate 6%-lit crescent Moon sinking fast into the horizon. You should be able to pick it out with binoculars. If so, try looking just below it for Regulus, the brightest star in the constellation of Leo. Regulus will be just 4.3° from the Moon. After months spent dominating the spring night sky, Leo is now on its way out.
A crescent Moon and ‘Earthshine’ will be visible this week.
Anadolu Agency via Getty Images
Thursday, July 23, 2020: a crescent Moon, ‘Earthshine’ and a rocket launch to the ISS
Have you ever seen “Earthshine,” sometimes called “planet-shine?” The phenomenon of the Moon’s darkened limb being subtly lit-up by sunlight being reflected by Earth is only visible to the human eye in the last and first few days of the Moon’s orbit of Earth. With the Moon 13% lit tonight after dark its an ideal time to try for “Earthshine.”
Today also sees a Russian Soyuz rocket launch from the Baikonur Cosmodrome, Kazakhstan, carrying the Progress spaceship to the International Space Station (ISS) on a scheduled cargo drop.
Friday, July 24, 2020: a crescent Moon and more ‘Earthshine’
About 22% lit and now in the constellation of Virgo, the Moon is nearing its perigee for the month—the closest it gets to Earth on its slightly elliptical monthly orbit. It’s another great opportunity to look for “Earthshine” as well as the sight of a delicate crescent Moon.
Sunday, July 26, 2020: the Moon and Spica
Now 44%-lit and visible in the south well before sunset, an almost First Quarter Moon will shine brightly above bright star Spica, the 15th brightest star in the night sky. Spica is around 250 light-years distant.
Wishing you clear skies and wide eyes.