Image: Sky map
Starry Night Software
This sky map shows the location of Mars near the moon in the southwest on May 28, 2012, as wellas the positions of Saturn and two bright stars, at 9 p.m. local time from mid-northern latitudes.
updated 5/27/2012 12:46:02 PM ET 2012-05-27T16:46:02

Monday evening brings us a first quarter moon, offering U.S. skywatchers a chance to close out the Memorial Day holiday with a lunar treat and the fading planet Mars.

The first quarter moon is also sometimes called the "half" moon, although as darkness falls across North America close inspection with binoculars or a small telescope may reveal that there is actually a little more than half of the moon illuminated by the sun. That's because the actual moment of first quarter occurred earlier in the afternoon at 4:16 p.m. ET or 1:16 p.m. PT.

When it gets sufficiently dark you'll also take notice of a rather bright yellow-orange star appearing well above and a bit to the moon's left. That’s not a star, however, but a once brilliant planet that continues to ebb in brightness: Mars. Look for this colorful world shining high in the southwest during dusk and lower in the west-southwest as night grows late.

Mars will remain prominent all evening, despite the fact that it will continue to slowly fade in the days and weeks to come as it gradually pulls away from the Earth. When the moon passes it by on Monday, it will still be shining at a respectable magnitude +0.5, which is just a trifle dimmer than the ruddy star Betelgeuse in Orion. [Amazing Pictures of Mars]

Astronomers measure the brightness of objects in the sky on a magnitude scale. The lower an object's magnitude number, the brighter it appears in the night sky. Small digits and negative number magnitudes denote the brightest night sky objects.

By the end of June, Mars will have faded fourth-tenths of a magnitude, to +0.9 (remember the higher the number, the fainter the object), making it just a bit brighter than Spica, the brightest star in the Virgo constellation. By that time its position will be about midway between Spica and the planet Saturn to its east and the bluish 1st-magnitude star Regulus in Leo to its west.

  1. Space news from
    1. KARE
      Teen's space mission fueled by social media

      Science editor Alan Boyle's blog: "Astronaut Abby" is at the controls of a social-media machine that is launching the 15-year-old from Minnesota to Kazakhstan this month for the liftoff of the International Space Station's next crew.

    2. Buzz Aldrin's vision for journey to Mars
    3. Giant black hole may be cooking up meals
    4. Watch a 'ring of fire' solar eclipse online

But Mars will then be edging toward Spica and Saturn and will have a striking interaction with those two objects later in the summer.

On June 21, Mars will leave the boundaries of Leo, where it has resided since the beginning of February, and moves into Virgo. On the North American evening of June 28, Mars will pass just 15 arc minutes – 0.25 degrees – south of the 3.8-magnitude star, Beta Virginis. To get an idea of how close that is, that’s one-half the apparent width of the moon.

Because Mars soon comes to eastern quadrature – a point in the sky that is 90 degrees east of the sun – on June 7, it should now appear distinctly gibbous in even a very small telescope. Most amateur telescopes won’t be showing any substantial detail on Mars; in fact by the end of June its apparent diameter will have shrunk to 6.6 arc seconds, which is less than half the size Mars appeared to us in early March when it was closest to earth at 62.6 million miles (100.7 million kilometers) away.  In contrast, by Jun. 30, Mars will have receded to a distance of 131.8 million miles (212.1 million km) from us.

But at least we have a spacecraft heading for the Red Planet that is drawing near!

The Mars Science Laboratory, which launched in November 2011, is carrying the 1-ton Curiosity rover which is scheduled to land on the Martian surface early on Aug. 6 to begin a two-year prime mission. Curiosity's landing site is near the base of a mountain inside Gale Crater, near the Martian equator. Researchers plan to use Curiosity to study layers in the mountain that hold evidence about wet environments of early Mars.

Editor's note: If you snap an amazing picture of the moon and Mars that you'd like to be considered for use in a story or gallery, please send images and comments to managing editor Tariq Malik at

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York.

© 2013 All rights reserved. More from

Photos: Month in Space: January 2014

loading photos...
  1. Southern stargazing

    Stars, galaxies and nebulas dot the skies over the European Southern Observatory's La Silla Paranal Observatory in Chile, in a picture released on Jan. 7. This image also shows three of the four movable units that feed light into the Very Large Telescope Interferometer, the world's most advanced optical instrument. Combining to form one larger telescope, they are greater than the sum of their parts: They reveal details that would otherwise be visible only through a telescope as large as the distance between them. (Y. Beletsky / ESO) Back to slideshow navigation
  2. A balloon's view

    Cameras captured the Grandville High School RoboDawgs' balloon floating through Earth's upper atmosphere during its ascent on Dec. 28, 2013. The Grandville RoboDawgs’ first winter balloon launch reached an estimated altitude of 130,000 feet, or about 25 miles, according to coaches Mike Evele and Doug Hepfer. It skyrocketed past the team’s previous 100,000-feet record set in June. The RoboDawgs started with just one robotics team in 1998, but they've grown to support more than 30 teams at public schools in Grandville, Mich. (Kyle Moroney / AP) Back to slideshow navigation
  3. Spacemen at work

    Russian cosmonauts Oleg Kotov, right, and Sergey Ryazanskiy perform maintenance on the International Space Station on Jan. 27. During the six-hour, eight-minute spacewalk, Kotov and Ryazanskiy completed the installation of a pair of high-fidelity cameras that experienced connectivity issues during a Dec. 27 spacewalk. The cosmonauts also retrieved scientific gear outside the station's Russian segment. (NASA) Back to slideshow navigation
  4. Special delivery

    The International Space Station's Canadian-built robotic arm moves toward Orbital Sciences Corp.'s Cygnus autonomous cargo craft as it approaches the station for a Jan. 12 delivery. The mountains below are the southwestern Alps. (NASA) Back to slideshow navigation
  5. Accidental art

    A piece of art? A time-lapse photo? A flickering light show? At first glance, this image looks nothing like the images we're used to seeing from the Hubble Space Telescope. But it's a genuine Hubble frame that was released on Jan. 27. Hubble's team suspects that the telescope's Fine Guidance System locked onto a bad guide star, potentially a double star or binary. This caused an error in the tracking system, resulting in a remarkable picture of brightly colored stellar streaks. The prominent red streaks are from stars in the globular cluster NGC 288. (NASA / ESA) Back to slideshow navigation
  6. Supersonic test flight

    A camera looking back over Virgin Galactic's SpaceShipTwo's fuselage shows the rocket burn with a Mojave Desert vista in the background during a test flight of the rocket plane on Jan. 10. Cameras were mounted on the exterior of SpaceShipTwo as well as its carrier airplane, WhiteKnightTwo, to monitor the rocket engine's performance. The test was aimed at setting the stage for honest-to-goodness flights into outer space later this year, and eventual commercial space tours.

    More about SpaceShipTwo on PhotoBlog (Virgin Galactic) Back to slideshow navigation
  7. Red lagoon

    The VLT Survey Telescope at the European Southern Observatory's Paranal Observatory in Chile captured this richly detailed new image of the Lagoon Nebula, released on Jan. 22. This giant cloud of gas and dust is creating intensely bright young stars, and is home to young stellar clusters. This image is a tiny part of just one of 11 public surveys of the sky now in progress using ESO telescopes. (ESO/VPHAS team) Back to slideshow navigation
  8. Fire on the mountain

    This image provided by NASA shows a satellite view of smoke from the Colby Fire, taken by the Multi-angle Imaging SpectroRadiometer aboard NASA's Terra spacecraft as it passed over Southern California on Jan. 16. The fire burned more than 1,863 acres and forced the evacuation of 3,700 people. (NASA via AP) Back to slideshow navigation
  9. Where stars are born

    An image captured by NASA's Spitzer Space Telescope shows the Orion Nebula, an immense stellar nursery some 1,500 light-years away. This false-color infrared view, released on Jan. 15, spans about 40 light-years across the region. The brightest portion of the nebula is centered on Orion's young, massive, hot stars, known as the Trapezium Cluster. But Spitzer also can detect stars still in the process of formation, seen here in red hues. (NASA / JPL-Caltech) Back to slideshow navigation
  10. Cygnus takes flight

    Orbital Sciences Corp.'s Antares rocket rises from NASA's Wallops Flight Facility on Wallops Island, Va, on Jan. 9. The rocket sent Orbital's Cygnus cargo capsule on its first official resupply mission to the International Space Station. (Chris Perry / NASA) Back to slideshow navigation
  11. A long, long time ago...

    This long-exposure picture from the Hubble Space Telescope, released Jan. 8, is the deepest image ever made of any cluster of galaxies. The cluster known as Abell 2744 appears in the foreground. It contains several hundred galaxies as they looked 3.5 billion years ago. Abell 2744 acts as a gravitational lens to warp space, brightening and magnifying images of nearly 3,000 distant background galaxies. The more distant galaxies appear as they did more than 12 billion years ago, not long after the Big Bang. (NASA / NASA via AFP - Getty Images) Back to slideshow navigation
  12. Frosty halo

    Sun dogs are bright spots that appear in the sky around the sun when light is refracted through ice crystals in the atmosphere. These sun dogs appeared on Jan. 5 amid brutally cold temperatures along Highway 83, north of Bismarck, N.D. The temperature was about 22 degrees below zero Fahrenheit, with a 50-below-zero wind chill.

    Slideshow: The Year in Space (Brian Peterson / The Bismarck Tribune via AP) Back to slideshow navigation
  1. Editor's note:
    This image contains graphic content that some viewers may find disturbing.

    Click to view the image, or use the buttons above to navigate away.

  2. Editor's note:
    This image contains graphic content that some viewers may find disturbing.

    Click to view the image, or use the buttons above to navigate away.

  3. Editor's note:
    This image contains graphic content that some viewers may find disturbing.

    Click to view the image, or use the buttons above to navigate away.

  4. Editor's note:
    This image contains graphic content that some viewers may find disturbing.

    Click to view the image, or use the buttons above to navigate away.


Discussion comments


Most active discussions

  1. votes comments
  2. votes comments
  3. votes comments
  4. votes comments