Changing Planet

5 Sky Events This Week: Rare Celestial Shadow Dance and Leo Paws at the Moon

Innermost moon of Jupiter, Io and its shadow seen here by Cassini in 2004 as it swung-by the gas giant. Credit: Cassini Imaging Team, Cassini Project, NASA
Io, Jupiter’s innermost moon, and its shadow were caught in 2004 by Cassini as it swung past the gas giant. Courtesy of Cassini Imaging Team, Cassini Project, NASA

Hunt down a comet, chase Jupiter’s moons, and watch Earth’s moon cozy up to some of the night sky’s brightest planets and stars. 

Comet Visitor. After nightfall on Monday, June 2, and for the next few nights, the comet PanSTARRS (C/2012 K1) can easily be spotted through small backyard telescopes. This fuzz-ball comet was discovered in 2012 by astronomers using the Pan-STARRS telescope (hence its name) on top of Mauna Kea in Hawaii. It’s been steadily brightening ever since, and according to some predictions, it may well reach naked-eye brightness in the weeks or months ahead.

This skychart shows the position of comet PANSTARRS in the spring and early summer sky looking towards the north just under the bowl of the Big Dipper and above the constellation Leo, the lion.  Credit: NASA/JPL
This sky chart shows the position of the PanSTARRS comet in the spring and early summer sky as you look toward the north, just below the bowl of the Big Dipper and above the constellation Leo. Courtesy of NASA/JPL

The comet has now reached magnitude 8, and according to editors at Astronomy magazine, it can be picked up right below the bowl of the Big Dipper.

It will appear just 3 degrees east of Mu Ursae Majoris, one of the paws of the Great Bear constellation. Snapshots of the comet, like the one below taken from Italy on May 31 by Stefano Pesci, clearly shows a green gaseous glow around the comet and a nice tail forming.



Triple Jovian shadow.  On Tuesday three of Jupiter’s largest moons, Callisto, Europa, and Ganymede, will simultaneously cast shadows on the upper cloud deck of the largest planet in the solar system. Sky-watchers in eastern Europe and Africa are best placed to enjoy this rare transit, since it occurs during their nighttime. Keen-eyed backyard astronomers in North America can try looking during their daylight hours, but it will be a challenge.

Check out this computer simulation of this triple-shadow transit.

As seen through a small backyard telescope, three tiny black dots will cross the face of Jupiter from 15:22 UT (11:22 a.m. EDT) to 19:43 UT (3:43 p.m. EDT). Miss this triple play, and you’ll have to wait until January 2015 for the next one.

Skychart showing constellation Leo, the lion pawing the moon on the evening of June 3. Earth's companion will appear next door to Leo's brightest star, Regulus. Credit: SkySafari
In this sky chart the constellation Leo, the lion, paws the moon on the evening of June 3. Earth’s companion will be next door to Leo’s brightest star, Regulus. Courtesy of SkySafari

Moon and Leo.  Also in the early evening of Tuesday, June 3, you can look toward the west for the waxing crescent moon gliding just underneath the  constellation Leo and its brightest member, Regulus, which is 77 light-years away.

By Wednesday, June 4, the moon will have switched to the other side of the brilliant blue-white star.

This sky chart shows the moon parking itself next to the bright orange planet Mars on the evening of June 7, 2014. The pair will be visible throughout the overnight period. Credit: SkySafari
In this sky chart the moon parks itself next to the bright orange planet Mars on the evening of June 7. The pair will be visible throughout the night. Courtesy of SkySafari

Moon and Mars.  Face the southwest in the late evening on Saturday, June 7, and watch as the waxing gibbous moon pairs up with a bright orange  Mars, aka the red planet. The pair will be less than 2 degrees apart, making for a beautiful photo opportunity.

The color contrast between the moon and Mars will be particularly eye-catching.

Skychart showing the moon perched above Spica, the brightest star in the constellation Virgo. Credit: SkySafari.
Skychart showing the moon perched above Spica, the brightest star in the constellation Virgo. Courtesy of SkySafari.

Spica meets the Moon.  By Sunday, June 8, the moon will have slid farther south, positioning itself next to the bright star Spica, located 262 light-years away in the constellation Virgo, the Maiden.

The two will make for another stunning sky show, even for the unaided eye, appearing only 2 degrees apart, the width of only four lunar disks.

Follow Andrew Fazekas, the Night Sky Guy, on TwitterFacebook, and his website.

Andrew Fazekas, aka The Night Sky Guy, is a science writer, broadcaster, and lecturer who loves to share his passion for the wonders of the universe through all media. He is a regular contributor to National Geographic News and is the national cosmic correspondent for Canada’s Weather Network TV channel, space columnist for CBC Radio network, and a consultant for the Canadian Space Agency. As a member of the Royal Astronomical Society of Canada, Andrew has been observing the heavens from Montreal for over a quarter century and has never met a clear night sky he didn’t like.
  • Larry Sessions

    Thank you for the link to EarthSky.

  • scott finlayson

    Very interesting will mars be visible in the soythern hemisphere?obviously we see some differant stars but do we see the moon the same?

  • Mari Roden

    Thank you so much. I love the information.

  • Laura King

    Thank You for your work, in keeping me and the world informed,

  • Eileen Gmerek

    Since we are far from city lights, hoping the views be good. Thanks so much for the info.

  • Ima Ryma

    Out of the Oort cloud I was hurled,
    And to the Sun I set to roam.
    Any watching from any world,
    In this system that I called home?
    It took a while, but the third rock
    From the Sun glimpsed me at long last,
    Just a baby by comet clock.
    Into their space pool I was cast,
    By this rock’s beings to be one
    Of a few thousand comets known
    To light the sky when near the Sun,
    Perking curiosity prone.

    PanSTARRS telescope first found me,
    So guess what my Earthling name be!

  • konnie

    to ima ryma; I loved your poem

About the Blog

Researchers, conservationists, and others share stories, insights and ideas about Our Changing Planet, Wildlife & Wild Spaces, and The Human Journey. More than 50,000 comments have been added to 10,000 posts. Explore the list alongside to dive deeper into some of the most popular categories of the National Geographic Society’s conversation platform Voices.

Opinions are those of the blogger and/or the blogger’s organization, and not necessarily those of the National Geographic Society. Posters of blogs and comments are required to observe National Geographic’s community rules and other terms of service.

Voices director: David Braun (

Social Media