August 31, 2010 at 11:05 am | 2 Comments
But Not Goodbye
Last week an old friend and colleague, Jack Horkheimer, passed away. To most of the world, Jack was known as the Star Gazer (formerly the Star Hustler), for his little five-minute astronomy video short shows that aired on PBS for years and years. For many of us in the planetarium profession, Jack was a long-time colleague and director of the Miami Space Transit Planetarium. I’d known Jack since the early 1980s, when we met at a planetarium conference in Memphis, Tennessee. I remember we sat at a coffee shop, a bunch of us, swapping tall tales and telling jokes, and Jack had some of the funniest stories to tell about giving shows at his planetarium. I didn’t see Jack again until 1986, when we were all at a Voyager 2 flyby press event at JPL. He’d been popular as the Star Hustler for some years by then and he was at JPL to gather fodder for his shows and talks. I remember going out to a bar with Jack and another couple of his friends during that busy week, and again, we swapped tall tales and jokes.
The Jack Horkheimer I knew as a planetarian was quite a guy — maybe not always as swaggering as his Star Hustler (later renamed “Star Gazer”) persona, but always personable and friendly. He was a thoughtful guy, ready to help folks out when they needed it, and always up for sharing astronomy with anybody. His ideas about astronomy being for everybody inspired a number of us as we sought our own paths to sharing astronomy with the public. He was a public fixture and a planetarian to the core.
It was with great sadness that I heard of Jack’s death. He had moved to Miami many years ago, as he put it, to die from a respiratory ailment he’d had. The climate must have agreed with him, because he not only didn’t die — he thrived. In the end, his ailment took him away, but not before he brought astronomy to a wide audience. The world is poorer for his loss, but you know what? We’re all richer for having had him there all those years to point out the stars and bring the skies to everyone with his engaging Star Gazer series. RIP, Jack — and we’re all looking up!
August 27, 2010 at 11:21 am | 3 Comments
So, by now, you’ve probably heard that Mars is going to look as big as the full Moon tonight. It’s a very popular Internet meme these days, sent around by people who think it sounds cool but never stop to think about the physical situation that such a story represents.
Epic fail on their part. Don’t let it be one on yours.
Think about it. How far away is the Moon? I’ll tell you — it’s (on average, depending on where it is in its orbit) about 384,000 kilometers away from us.
Now, how far away is Mars? I’ll tell you that, too. When Mars and Earth are at their closest points in their orbits, Mars can be about 55 or 56 million kilometers away. That makes it look like a reddish point of light from our vantage point here on Earth.
Okay, now compare 384,000 with 55 million. BIG difference. It’s a big enough difference that Mars will always, always, always appear as a point of light in our sky. And the Moon will be brighter and bigger and look like… the Moon.
If Mars were to look as big as the full Moon in our skies, we would have BIG problems. Bigger than worrying about how it would look in our sky. Let me put it to you this way: if it were as big as the full Moon in our sky, we’d be looking for a way off-planet before the tidal forces broke both worlds apart. NASA explains it all pretty well here.
So, don’t believe the meme — don’t let some foolish person’s misunderstanding of science and planetary orbital mechanics live rent-free in your brain.
Instead, head out tonight and check out Mars and Venus after sunset. They look lovely, without all the need for breathless Internet/Web hype.
August 26, 2010 at 15:22 pm | Leave a Comment
What Are They Like?
It has been almost 20 years since the first extrasolar planets (worlds around other stars) were discovered. Astronomers suspected they existed, but since tiny worlds can get lost in the glare of their stars’ light, we had to wait until we had the right kinds of instruments to observe distant worlds circling other stars. Today, the number of confirmed exoplanets lies at just under 500, and that number changes almost daily.
The latest news in planet-hunting circles is the discovery of two planets orbiting a star called Kepler-9. The planets showed up in data taken by the Kepler mission, which is tasked to search for extrasolar planets in an area of the sky in the direction of the constellation Cygnus the Swan (which is high in the northern hemisphere sky these evenings).
Now, there have been lots of extrasolar planets discovered, but this is the first time two have been confirmed orbiting the same star. The planets, named Kepler-9b and Kepler-9c, have masses that are almost that of Saturn in our own solar system. Kepler-9b is the larger of the two and it orbits the star once every 19 days. The smaller Kepler-9c lies farther away and takes 38 days to make a trip around the star.
The Kepler spacecraft observed this system to tack down the precise length of each planet’s orbit around the parent star. This isn’t the only such system that the spacecraft has data for, but it’s the first to be confirmed — a big milestone for the team and the spacecraft.
The planets were discovered as the Kepler spacecraft’s camera measured tiny decreases in the star’s brightness–decreases that occur when a planet moves between us and the star. And yes, even something so small as a planet can have an effect on the star’s brightness, and Kepler is sensitive enough to detect those little dips in the star’s light. In addition, the distance between each planet and the star can be calculated by measuring the time between successive dips as the planet orbits the star. Small changes in the regularity of these dips can help astronomers determine the masses of planets and detect other non-transiting planets in the system. In fact, the data seem to indicate that there may be at least one other planet in the system–a world about 1.5 times the Earth’s radius that follows a scorchingly short 1.6-day orbit around the star. Kepler scientists are still taking data to make sure that this is another planet and not an anomaly in the data.
The artist’s concept of the two confirmed planets show that these are gas giant-like worlds, so they’re not likely to be places where life is going to exist — at least life as we know it. And, if there IS another planet that’s closer to Earth-size? Well, it’s not likely to be a very hospitable place either. It’s likely a scorchingly hot place with little opportunity for life to take hold.
Kepler’s discovery is the second in a pair of exoplanet finds reported this week. The European Southern Observatory announced earlier that it has found a star that may have at least five planets orbiting around it. Astronomers used the HARPS spectrograph attached to the ESO’s 3.6-meter telescope in Chile to search for the existence of planets in the system. Unlike the Kepler mission, which checks for dips in light intensity of stars with planets in orbit around them, the HARPS insrtrument looks for stellar motions that indicate the existence of planets. The amount of motion tells them the mass of the planets that may exist, and helps them deduce the orbits of those distant worlds. The measurements correspond to planets with masses between 13 and 25 Earth masses. They appear to orbit the star with periods ranging from about 6 to 600 days. These planets lie between 0.06 and 1.4 times the Earth–Sun distance from their central star. This is actually pretty well-populated system with five massive planets located within 1.4 AU. By comparison, the Sun has only four planets — and small ones at that — in roughly the same space.
The science of planetary detection is a major growth area in astronomy. With Kepler’s ongoing mission and the ground-based work being done at places such as ESO, I think it’s only a matter of time before the community of worlds that we can detect will be well over a thousand. Now… if we could only find one with life on it!
August 23, 2010 at 21:35 pm | Leave a Comment
A Big Part of Life Flies Under the News Radar
I just got through browsing the CNN.com website and after reading about vapid celebrity pregnancy stories, flight attendants venting about passengers, endless food discussions, weird sports stories, and — of course — the actual “news” (which seems to be topped by a story about Tiger Woods’s divorce), it struck me that there wasn’t one story about actual science. And no, the fact that a misguided federal judge threw out stem cell research permissions is NOT science news. It’s politics, as usual.
Oh, sure, there’s a “Tech” section on CNN — a sort of vapid ghetto of techie news that seems to be mostly around viral apps. It supposedly has science — at least, that’s the excuse that CNN gave when it canned Miles O’Brien in order to give the stunningly self-aware Anderson Cooper a tech news segment on cable. But, the online news seems to cover such non-science stories as undoing bad emails, a Bieber remix going viral, and how tough it is to sell home viewers on 3D.
So, where’s the actual science? You know, the stories about astronomy discoveries and physics breakthroughs and stuff like that? It’s nowhere to be found in the morass of stories that are really advertising for techie stuff in disguise. I miss the old days when news outlets actually covered ALL the news, including the science.
Science is a big part of our lives, folks. From the latest HST discoveries to in-depth stories about research finds in biology, archaeology, paleontology, chemistry, geology, physics, and so forth — science is an endeavor that people do — and one that actually advances our knowledge of the cosmos and how it ticks. How is this NOT a rich field of news?
The good news is that there are outlets that do cover news — Science News — for example, is a good one. And, it won’t turn you into a geek to read it. The stories are fantastic and fascinating. I read it every week and have done so for years. There’s also Science Daily, which is also readable and interesting and won’t transform you into a pocket-protector-wearing nerd. And, Discover – which hosts a number of good writers of my caliber (and better) — who bring you all kinds of great science news. Reading THAT site won’t hurt you either. It’s good for your mental and intellectual health.
What science sites are YOU reading? Are any of them in the mainstream media? Do they cover more than tech apps? If so, let me know. I’ll compile a list and post them here.
August 17, 2010 at 12:26 pm | Leave a Comment
Finding Pulsars with Your Home Computer
Last week the news hit the stands about a pulsar discovered in data being crunched by home computers. This little bit of serendipitous astronomy research was done using a distributed-computing progject program called Einstein@Home. It’s a distributed data-crunching project that lets people devote duty cycles on their home computers to science research. The data came from the Arecibo Observatory in Puerto Rico (the one that keeps getting threatened with closure because some folks consider it unimportant to radio astronomy).
The pulsar, which lies in the direction of the constellation Vulpecula, is about 17,000 light-years away. This spinning husk of a dying star was discovered in data that was crunched by three people — two in Iowa and one in Germany. That had to pretty exciting to know that one’s computer helped find one of nature’s oddball objects.
Einstein@Home isn’t the only distributed computing project out there. The grand-daddy of ‘em all is SETI@Home, which crunches through signals from several sources to find any possible messages from intelligent life that might be out there messaging us from the cosmos. But, there are others — and if you’re looking for something to occupy your computer when you’re not busy with it, check ‘em out here. There are projects in astronomy, biology, medicine — you name it, there’s a distributed computer project for you.
I spent several years with a computer dedicated to such a distributed project and it felt pretty good to know that my unused duty cycles were going for a good scientific cause. You might get the same good feeling, too — and who knows? You might help discover something really big!
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Image of Horsehead Nebula: T.A.Rector (NOAO/AURA/NSF) and Hubble Heritage Team (STScI/AURA/NASA)
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