Jupiter rises a few hours after dark throughout October. It doesn’t transit until the wee hours of the morning ... but it’s far enough north that you should be able to get some nice previews of this fall’s Jupiter opposition.
Mercury and Mars are low in the western evening sky. Mercury stays low in the twilight all month. Mars is a bit higher, but it’s low and distant, so if you’re hoping to see lots of Mars surface detail, you’ll be better off scanning the latest downloads from the Mars Curiosity rover, which pulled off its tricky landing a few months ago with flying colors and is now sending lots of great high-resolution images back to Earth.
Did you know that the people who drive the Mars Rovers live on Mars time, not Earth? Their schedules follow the Martian day, called a “sol” – 39-1/2 minutes longer than an Earth day – so that every couple of weeks, they’re working all night, sleeping in the daytime.
Apparently NASA has found that’s easier for workers than to try to sleep on Earth time but work during the Martian day.
For naked eye observers bound to normal Earth schedules, keep an eye on Mars around the third weekend of October, when it passes a few degrees away from Antares: offering a nice opportunity to compare Mars to the “Rival of Mars”, the anti-Ares.
Uranus and Neptune are well placed for observing all night. Uranus may be a bit more challenging than usual, located off in the middle of nowhere, the dark depths between Pisces, Cetus and Aquarius. If you’re not familiar with that area, try using the two “rump” stars of the Great Square of Pegasus as pointers – Uranus is bright enough that a binocular sweep in the right direction should be able to pick it up.
Neptune, too, is tricky, off the left horn of Capricornus. It’s not bright enough that it will stand out as you’re sweeping with binoculars or a finderscope, so use a star chart: there are a couple of 4th and 5th magnitude stars in the area that you can use as guides.
Pluto joins Mercury and Mars as an early evening object. It’s higher than the other two, setting a little before 11pm, but it never gets very high in the sky. So it’ll be a tough hunt down there in the Milky Way horizon spurge.
Venus is in the morning sky, making a close double with Regulus on the morning of October 3. And a few weeks later, early risers with a good dark eastern horizon have a good chance at the zodiacal light, a faint band of light stretching up along the ecliptic.
Aside from Mars Curiosity, another spacecraft was in the news recently. Voyager 1, originally launched in 1972, is preparing to leave the solar system. It’s already in the heliosheath – the “shock wave” region where the particles of the solar wind crowds up against the interstellar wind. NASA expects it to cross the heliopause soon, the outer edge of the sheath, where the solar wind become undetectable against the background interstellar wind. Astrophysicists debate the exact location of the heliopause, so the data beaming back to us should be interesting. (see: http://www.jpl.nasa.gov/news/news.php?release=2012-249)
Of course, what it actually means to leave the solar system is open to debate. Voyager 1 is now about 122 AU (about 11 billion miles) from the sun. That’s far outside the Kuiper belt asteroids, which extend from about 30 to 50 AU – but surely the Oort cloud, at a staggering distance of 50,000 AU, nearly a light year, is also part of our solar system? The comets and smaller particles comprising the cloud are held there by the sun’s gravity so they sure seem like part of the solar system.
But enough about distance – as a stargazer, I found myself curious where Voyager 1 is in the sky. Not that there’s a chance of seeing such a tiny, distant object ... but isn’t it fun to know where to look, even if you can’t see it? Look for Voyager in Ophiuchus, about midway between Kappa Ophiuchi and Alpha Herculis (Rasalgethi), and about 45 arcminutes southeast of the 5th magnitude star 60 Herculis.
In a bit over 40,000 years, Voyager will pass relatively close to a red dwarf star called Gliese 445. That star is in Camelopardalis, just a tad west of the midway point between Polaris and Giausar, the last star in Draco’s tail. It’s magnitude 10.8.
Hey, wait a minute. Voyager 1 is in Ophiuchus, but it’s heading toward a star in Camelopardalis? That’s about 75 degrees away. Wouldn’t you think that the spacecraft and the star it’s heading toward would be pretty much lined up by now?
Ah ... but that assumes Gliese 445 is standing still, and it isn’t. It’s moving fairly fast, as stars go, and 40,000 years gives it plenty of time to move somewhere else. I tried to verify that Gliese 445’s proper motion will bring it into Ophiuchus by the year 40,272 AD, but I haven’t found any reliable way to check that.
Even getting the sky locations of Voyager and Gliese 445 wasn’t as easy as I expected. You can get accurate coordinates from JPL’s online HORIZONS simulator, or general coordinates from the “Spacecraft escaping the solar system” table on Heavens Above. Then I could look those coordinates up in a planetarium program or on a star chart. But curiously, the only site I found that would display an actual labeled star chart was Wolfram Alpha. (http://www.wolframalpha.com/input/?i=where+is+voyager+1 ) Just type in “where is voyager 1” or “where is gliese 445”. The star charts aren’t great, but they’re better than anything I found on the various astronomy sites and in planetarium programs. Keep Wolfram Alpha in mind for your difficult astronomy queries.
Curious about the rest of our long-distance spacecraft? Pioneer 10, our second most distant spacecraft at 106 AU from the sun, is in Taurus, a few degrees SW of Alnath, the southernmost star in Auriga. Pioneer 10 launched five and a half years earlier than Voyager 1, but Voyager got a speed boost from a gravity slingshot around Saturn and Titan that boosted it to 17.26 km/s (about 38,600 miles per hour), the fastest spacecraft in history, even faster than the speedy 15 km/s New Horizons Pluto probe.
Voyager 2, third most distant, is in the southern constellation of Telescopium, too far south for us to see it in San Jose. Pioneer 11, fourth at a measly 86 AU, is in Scutum, a few degrees south of M11.New Horizons, still only 23.9 AU out, lies in the most interesting observing location: it’s in Sagittarius, just a tad east of the midway point between M22 and M25 – pretty much right where Pluto is.
Finally, coming back to Voyager 1: did you know that the music and other sounds of Earth sent on the golden record on the Voyager spacecraft isn’t easily available to people still here on Earth?
We have our crazy copyright laws to thank for that. When Carl Sagan originally got the rights to put each piece on the Voyager record, those rights didn’t cover anything except the records that launched with the two Voyagers ... not reprints for humans to listen to.
Later, Warner Multimedia bought the rights to the collection, publishing “Murmurs of Earth” as a CD in 1992. But it’s long since gone out of print, and used copies are rare and start at around $85.
You might think that a collection compiled in 1972, based mostly on much older works, would be in the public domain by now ... but that’s not how copyright works these days. So if you want to hear the sounds of Earth as collected by Sagan and the Voyager team ... you’d have better luck as an alien.
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