Stargazing Tonight: Planets and Fading NEOWISE

Let’s start the last week of July with the latest Astronomy Skylights. Keep reading and you’ll learn more about upcoming astronomical events and planets that are worth to gaze on tonight. Of course, we won’t miss out on the well-known comet NEOWISE, which has faded to a binoculars target.

Mercury gets lower

Speedy little Mercury was at its greatest western elongation last week, so it will drop a little lower every morning as it descends sunward. Look for the planet sitting very low in the east-northeastern sky between about 5 and 5:30 a.m. in your local time zone.

Venus meets the Ruby Star

Early risers have been amazed by extremely bright Venus, which will rise in the east at about 3 am local time this week, and remain visible until sunrise as it climbs the sky. On Friday, July 31, Venus will be positioned close to the upper left of the Ruby Star (119 Tauri). That star is a giant, aging, pulsating variable star that shines with a deep red color. The pair will be visible with binoculars and backyard telescopes until the sky starts to brighten.

How to find Uranus

Blue-green Uranus is rising shortly after midnight local time this week. It’s visible with unaided eyes and in binoculars under a dark sky. Look for the magnitude 5.8 ice giant planet sitting in southern Aries below its brightest stars Hamal and Sheratan.

Space missions to Mars

Mars is steadily increasing in disk size and brightness because Earth is traveling towards it this summer. Mars is one of the main interests of scientific study this month:

• The United Arab Emirates launched the Hope orbiter to Mars on July 19;
• China launched its own Tianwen-1 orbiter and rover to Mars on July 23;
• NASA is scheduled to launch the Perseverance Rover to Mars on July 30.

Neptune before dawn

Dim and distant Neptune is located to the west of Mars, among the stars of eastern Aquarius. The planet rises at about 10:30 pm local time and then climbs higher until just before dawn, when you’ll get your clearest view of it, halfway up the southern sky. But keep in mind that Neptune is hard to find without a computerized telescope.

Saturn and Jupiter dazzling in July

The evening planets are easy ones to see – Saturn and Jupiter! Somewhat dim, yellow-tinted Saturn is chasing brighter, whiter Jupiter across the night sky – lagging it among the stars of eastern Sagittarius. Last week, the Earth passed between Saturn and the Sun, placing us the closest to the giant planet for 2020. It’s still a spectacular sight in backyard telescopes.

Even a small telescope will show Saturn's rings and several of its brighter moons – especially its largest moon, Titan! During this week, in the late evening, it will migrate counter-clockwise around Saturn, moving from the upper right of Saturn to the lower left of the planet from night to night.

Jupiter will already be shining brightly in the eastern sky at dusk. Good binoculars will reveal Jupiter’s four large Galilean moons as they dance around the planet. Even a modest-sized telescope will show Jupiter’s brown equatorial belts and the famous Great Red Spot (or GRS, for short) if the air is steady. Due to Jupiter’s 10-hour period of rotation, the GRS appears every second or third night from a given location on Earth.

Not-so-Bright Comet NEOWISE

After putting on an exciting show for a couple of weeks, Comet C/2020 F3 NEOWISE has passed Earth on its way back out of the solar system – perhaps to return in about 6000 years. The comet’s increasing distance from Earth and the continuous reduction in heating from the Sun are both causing NEOWISE to fade in brightness over time. It will be visible in binoculars and telescopes for another couple of weeks, and then become a telescope-only target after about mid-August.

This week, comet NEOWISE will only become observable once the moonlit sky darkens enough to allow you to see its faint glow. Then it will be carried lower and lower for several hours as the Earth turns. The comet will be in the sky below and between the star Alkaid at the end of the Big Dipper’s handle, and the very bright star Arcturus. You can find the accurate position of the comet and more additional information about it using Star Walk 2. Search for “NEOWISE”, tap on the comet’s name in the lower part of the sky map, and then tap on the “Figures” section to see the rise and set times, distance from the Earth, etc.