4 Sky Events This Week: Ice Giants and Deep Sky Jewels

A snapshot of 3000 light year distant open star cluster Messier 35 through a large telescope. This week Mercury will act as a guide to tracking down before dawn in the east. Credit: N.A.Sharp/NOAO/AURA/NSF
A snapshot of the open star cluster Messier 35, 3,000 light-years away. This week Mercury will act as a guide to tracking it down before dawn in the east. Courtesy of N. A. Sharp/NOAO/AURA/NSF

Ice giants dancing with the moon and a ring left by a dying star offer plenty to hunt for in the heavens this week.

Mercury and the Messier 35 star cluster. About 45 minutes before local sunrise on Tuesday, July 15, look for a very faint Mercury in the low northeastern sky.  Make sure you find an observation point without any obstructions, since the elusive naked-eye planet will be only about 10 degrees above the horizon—the width of your fist at arm’s length.

The planet does shine brightly at magnitude 0, but if you’re having difficulty finding it, then use superbright Venus, just above it, as a guide.

As an added challenge, use binoculars to spot the fifth magnitude star cluster known as Messier 35, about 3 degrees north of Mercury. That’s roughly the distance of six full moons side by side or half the field of view in a typical pair of binoculars.

This sky chart shows Mercury, Venus, and Messier 35 (M 35) at dawn on June 15, 2014. Credit: SkySafari

At about 3,000 light-years from Earth, this open cluster sits at the foot of the Gemini twins. It’s about 24 light-years across and contains well over 500 stars, a few dozen of them easily picked up with a low-magnification telescope or binoculars.

Moon and Neptune.  Late on Tuesday, July 15, look toward the low eastern sky for the waning gibbous moon and the 8th magnitude Neptune, rising together in the constellation Aquarius.

The pair will appear closest together for telescope users from Europe through Asia, Africa, and Australia, where they will be separated by only 5 degrees, equal to the width of your three middle fingers held at arm’s length.

Moon and Uranus.  By the early morning of Friday, July 18, the moon will have slid toward the east and parked next to another ice-giant planet, Uranus.

Within the faint zodiacal constellation Pisces, the two celestial objects will appear to be just a bit over one degree apart. This tight conjunction will make it easy to find the 5th magnitude planet just below the moon.

This close encounter will best be seen from North and South America.

This sky chart shows the relative positions of the waning gibbous moon and Uranus on June 18, 2014. Credit: SkySafari
This sky chart shows the relative positions of the waning gibbous moon and Uranus on July 18, 2014. Courtesy of SkySafari

Amazingly, this giant planet, with a diameter nearly four times that of Earth, looks like a tiny green disk even through a telescope. That’s because it’s so far away—nearly two billion miles (nearly three billion kilometers).

In fact, Uranus is so far from us that sunlight reflecting off its cloud tops takes about 243 minutes to reach us here on Earth.

Ring Nebula in Lyra. On Saturday, July 19, the  moon is out of the evening sky, making this an ideal time to hunt down a small but pretty planetary nebula, a colorful bubble of gas left behind by a dying star.

Start your hunt for the Ring Nebula, also known as Messier 57, by looking high in the southeast for the star Vega and its constellation Lyra, or the Harp, which marks the brightest corner of the famous Summer Triangle pattern of stars.

Detailed finder chart for the Ring Nebula in the constellation Lyra. Credit: Starry Night software/ A.Fazekas
This finder chart locates the Ring Nebula in the Lyra constellation. Credit: Starry Night software/A. Fazekas

Resembling a triangle hitched to a parallelogram, Lyra is one of the smallest but most easily recognized classical constellations, one that’s visible all summer long.

The Ring Nebula is located halfway along a line between the two stars forming the trapezoid wall that’s farthest from Vega.

Close-up view showcasing the true beauty of the Ring Nebula (M57) as seen by the Hubble Space Telescope. Credit: The Hubble Heritage Team (AURA/STScI/NASA)
A close-up view of the Ring Nebula (M57), as seen by the Hubble Space Telescope, showcases its beauty. Courtesy of the Hubble Heritage Team (AURA/STScI/NASA)

The planetary nebula is visible only through high-magnification telescopes, and it looks like a small, pale ring. Long-exposure photographs reveal the nebula in all its glory, showing the expanding ring of hot gas in a beautiful rainbow of colors.

Though it seems of just modest size at the eyepiece, the nebula is actually a one-light-year-wide shell of gas thrown off by a dying sun-like star more than 2,300 light-years from Earth.

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Changing Planet

Meet the Author
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.