Sky Events

(revised 11/15/09)

Planets. Jupiter continues to rule the evening sky. Look to the south after nightfall: the brightest "star" there is Jupiter.

Venus is still visible just above the horizon before sunrise.

International Space Station/Space Shuttle. The International Space Station (more info here), the largest satellite in orbit and the only permanent one inhabited by human beings, is occasionally visible to the naked eye. It looks like a moving star. Its brightness varies, but it can rival the brightest planets and outshine the brightest stars when conditions are optimum.

Space Shuttle Atlantis is scheduled to launch Monday morning, Nov. 16, on an 11-day supply trip to the Station. It happens that there are no really high, bright passes for either craft until Nov. 24, but then we have a couple very good opportunities. Here are details.

Tues., Nov. 24, 5:56-5:59 p.m. The joined spacecraft will rise in the northwest (NW). They'll reach an altitude* of 46 degrees (about halfway up the sky) in the NE, and disappear in the Earth's shadow soon thereafter in the ENE (altitude 43 d). Magnitude* will be -3.1, brighter than any visible star or planet.

Wed., Nov. 25, 6:18-6:21 p.m. Rises WNW; peaks (altitude 48 degrees) in SW; disappears soon after in Earth's shadow in SSW (alt. 44 d). Magnitude -2.5, significantly fainter than yesterday's and tomorrow's passes, but Atlantis should be undocked and may be far enough from the ISS to be seen separately tonight (see tomorrow's entry).

Thur., Nov. 26, 5:05-5:11 p.m. Rises WNW; peaks (48 d) in NNE; sets ESE. Magnitude -3.0. If the mission is on schedule, Atlantis will be separated, flying independently some distance ahead of or behind the Station. The day before a landing is an excellent opportunity to see both objects, one following the other across the sky.

Fri., Nov. 27, 5:27-5:33 p.m. Rises WNW; peaks a bit higher (52 d) in SW; sets SE. Mag. -2.5. The Shuttle should have landed by this pass; but if the mission was delayed, perhaps by bad weather, it might still be in orbit.

There are other, less favorable appearances during the next couple of weeks. For more information about the ISS, and about other satellites' appearances (including the amazing Iridium flares mentioned in South Jersey Skies for June 14), look at Heavens Above (from where the preceding information was obtained, to be honest).

* Altitude: angular distance in degrees above horizon, NOT distance in miles above Earth's surface. Straight overhead is 90 degrees, halfway up the sky is 45, the horizon is 0.

  Zenith: the point straight overhead.

  Magnitude: brightness. The brightest star in the winter sky, Sirius, has a magnitude of -1.4 (negative numbers are brighter); the brightest summer star, Vega, is at 0.0. Jupiter stands at -2.5, Venus at -4.0. The faintest star visible to someone with excellent eyesight is around +6. The Sun is -26! Magnitude estimates for the Station and Shuttle are typically underestimates: they usually appear significantly brighter than the numbers would lead you to expect. Also note: an evening pass starts out quite dim (because the Sun is shining mostly on the part of the spacecraft facing away from us). The satellite becomes brighter as it reaches its peak altitude. So have patience: don't give up too soon! Sweep your eyes along the expected path; look for a moving dot that doesn't blink. Morning passes start out a bit brighter, so are easier to pick up right away.

  Weather conditions: as I tell my students, I can't be held responsible for anything that happens less than 100 miles above the Earth's surface.

Star charts, sky maps. One of the most comprehensive star charts available is at SkyMaps.com.

Questions about this page? Contact the planetarium director.

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