Mars meets Messier Objects
Mars meets Messier Objects
This Week’s Sky: February 17 to 23

As the Moon occults Mars and passes by Jupiter before turning toward Saturn, here are the highlights in This Week’s Sky.

As the Moon occults Mars and passes by Jupiter before turning toward Saturn, here are the highlights in This Week’s Sky.

Monday, February 17 pre-dawn – Mars meets Messier Objects

Mars meets Messier Objects

In the southeastern pre-dawn sky for several days starting on Monday, February 17, the orbital motion of Mars (red path with dates and times) will carry the planet close to several bright deep sky objects in northern Sagittarius. On Monday, look for the Trifid Nebula (Messier 20) and the open cluster Messier 21 sitting less than a finger’s width to the upper left (or 0.5° to the celestial north) of Mars. The Lagoon Nebula (Messier 8) will be positioned below Mars. Several days later, Mars will pass below bright Messier 24, dimmer Messier 18, and Messier 25. Some of the deep sky objects will be visible in binoculars (red circle) under dark sky conditions.

Tuesday, February 18 from 12:25 to 13:50 GMT – Old Moon Occults Mars

Old Moon Occults Mars

In the southeastern morning sky on Tuesday, February 18, the waning crescent Moon will occult Mars for observers in North America (except western Canada & Alaska), most of Central America, the Caribbean, northern South America, the southern tip of Greenland, and the Azores. In the Eastern Time zone, the event will begin in daylight at 7:25 a.m. EST when the bright, leading limb of the Moon covers Mars. The planet will re-appear from behind the Moon’s opposite, dark limb at 8:50 a.m. (Exact ingress and egress times vary by location.) Binoculars and backyard telescopes (red circle) will show the event – although telescopes will flip and/or invert the image shown here. Observers located in the Central, Mountain, and Pacific time zones will see the encounter in a darker sky.

Wednesday, February 19 pre-dawn – Old Moon Meets Jupiter

Old Moon Meets Jupiter

In the southeastern pre-dawn sky on Wednesday, February 19, the slim crescent Moon will sit less than 4 finger widths to the upper right (or 4 degrees to the celestial southwest) of very bright Jupiter. Both objects will appear together in binoculars (red circle), and the pairing will make a lovely wide-field photograph when composed with local landscape features. This meeting will also allow you to later find Jupiter in the morning daylight sky using the Moon as a reference. At around 21:00 GMT, observers in Antarctica and southern South America will see the Moon occult Jupiter in daylight.

Thursday, February 20 before sunrise – Crescent Moon near Saturn

Crescent Moon near Saturn

For a short time before sunrise on Thursday, February 20, look very low in the southeastern sky for the very slim crescent Moon sitting about two finger widths to the lower right (or 2.3 degrees to the celestial southwest) of very bright Saturn. Both objects will appear together in binoculars while the Sun remains safely hidden below the horizon. Brighter Jupiter and Mars will be positioned 10 and 24 degrees, respectively to Saturn’s upper right.

Sunday, February 23 at 15:32 GMT – New Moon

New Moon

At its new phase, the Moon is travelling between the Earth and the Sun. Since sunlight is only reaching the side of the Moon aimed away from us, and the Moon is in the same region of the sky as the Sun, the Moon is hidden from view for about a day.

Chris Vaughan is a science writer, geophysicist, astronomer, planetary scientist and an “outreach RASCal.” He writes Astronomy Skylights, and you can follow him on Twitter at @astrogeoguy. He can also bring his Digital Starlab portable inflatable planetarium to your school or other daytime or evening event. Contact him through AstroGeo.ca to tour the universe together.

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