While driving a couple weeks ago, I happened to catch a meteor shooting across the sky:
Saw one of the coolest things ever tonight: a meteor burning up in the lower atmosphere. Super bright, exploded at the end like a firework.
It turned out that “one of the coolest things ever” wasn’t hyperbole. You see, earlier that day over the UK, a meteor streaked across the sky for about 50 seconds:
And then the one I saw happened about two-and-a-half hours later. Spurred by this unlikely coincidence, mathematician Esko Lyytinen of the colorfully named Finnish Fireball Working Group of the Ursa Astronomical Association did some calculations and determined that the two events were actually the same meteor.
He believes a large body grazed the upper atmosphere, dipping to an altitude of 33 miles (53 km) over Ireland before escaping back to space. Because it arrived moving at only about 8 miles (13 km) per second, barely above Earth’s escape velocity, it lingered for more than a minute as it crossed the sky. (This explains why some witnesses mistook it for reentering spacecraft debris.)
Lyytinen says the brief atmospheric passage took its toll. As the meteoroid broke apart, its velocity dropped to just 5.7 miles (9.2 km) per second, too slow to make an escape back to space. Instead, it became a temporary satellite of Earth, looping completely around the globe before reentering the atmosphere — this time for good. “It looks now that the fireball witnessed 155 minutes later in U.S. and Canada, may have been one fragment of the British fireball, most probably the biggest one,” Lyytinen explains.
These earth-grazers are not common but they do happen from time to time. But a visible Earth grazing meteor that enters the atmosphere twice? Unprecedented. So cool! (thx, alex)
The rest of you can have your Olympics, but the early August event I’m most looking forward to is the arrival on Mars of the Curiosity rover. But NASA has had someproblems in the past delivering payloads to Mars, so this is going to be somewhat of a nail-biter. If you haven’t seen it, Curiosity’s Seven Minutes of Terror is well worth watching to see the logistical challenge of getting the rover down to the surface.
Curiosity will hopefully land on the surface on Aug 6 at about 1:30 am ET.
Venus passed in front of the Sun yesterday for the last time until 2117. The transit took almost seven hours but this NASA video shows it in under a minute.
Cory Poole made this video of the annular solar ecplise yesterday using 700 photographs from a telescope with “a very narrow bandpass allowing you to see the chromosphere and not the much brighter photosphere below it.”
Cory says: “The filter only allows light that is created when hydrogen atoms go from the 2nd excited state to the 1st excited state.” Very cool.
The Dyson sphere, also referred to as a Dyson shell, is the brainchild of the physicist and astronomer Freeman Dyson. In 1959 he put out a two page paper titled, “Search for Artificial Stellar Sources of Infrared Radiation” in which he described a way for an advanced civilization to utilize all of the energy radiated by their sun. This hypothetical megastructure, as envisaged by Dyson, would be the size of a planetary orbit and consist of a shell of solar collectors (or habitats) around the star. With this model, all (or at least a significant amount) of the energy would hit a receiving surface where it can be used. He speculated that such structures would be the logical consequence of the long-term survival and escalating energy needs of a technological civilization.
Needless to say, the amount of energy that could be extracted in this way is mind-boggling. According to Anders Sandberg, an expert on exploratory engineering, a Dyson sphere in our solar system with a radius of one AU would have a surface area of at least 2.72x1017 km2, which is around 600 million times the surface area of the Earth. The sun has an energy output of around 4x1026 W, of which most would be available to do useful work.
The downside: we’d have to part with Mercury to do it.
And yes, you read that right: we’re going to have to mine materials from Mercury. Actually, we’ll likely have to take the whole planet apart. The Dyson sphere will require a horrendous amount of material-so much so, in fact, that, should we want to completely envelope the sun, we are going to have to disassemble not just Mercury, but Venus, some of the outer planets, and any nearby asteroids as well.
At Forbes, Alex Knapp explains why Dvorsky’s scheme and timeline might not work.
I emailed Astronomer Phil Plait about this project, who told me in no uncertain terms that the project doesn’t make sense.
“Dismantling Mercury, just to start, will take 2 x 10^30 Joules, or an amount of energy 100 billion times the US annual energy consumption,” he said. “[Dvorsky] kinda glosses over that point. And how long until his solar collectors gather that much energy back, and we’re in the black?”
I’ve spent years studying all this, and it still sometimes gets to me: just how flipping BIG the Universe is! And this picture is still just a tiny piece of it: it’s 1.2 x 1.5 degrees in size, which means it’s only 0.004% of the sky! And it’s not even complete: more observations of this region are planned, allowing astronomers to see even deeper yet.
Here’s a full view of the image that looks sorta unimpressive:
Indian lunar orbiter Chandrayaan-1 has discovered a large cave on the Moon. Aside from the hey, cool, there’s a cave on the Moon factor, the other big feature of the cave is its constant and temperate temperature.
Temperatures on the moon swing wildly, from a maximum of 262 degrees Fahrenheit to a minimum of -292. The cave holds steady at a (relatively) comfortable -4, since the moon’s weather can’t penetrate its 40-foot-thick wall. It could also protect astronauts from “hazardous radiations, micro-meteoritic impacts,” and dust storms, according to paper published by the journal Current Science.
This equation’s initial purpose, he wrote, was to put meaningful prices on the terrestrial exoplanets that Kepler was bound to discover. But he soon found it could be used equally well to place any planet-even our own-in a context that was simultaneously cosmic and commercial. In essence, you feed Laughlin’s equation some key parameters — a planet’s mass, its estimated temperature, and the age, type, and apparent brightness of its star — and out pops a number that should, Laughlin says, equate to cold, hard cash.
At the time, the exoplanet Gliese 581 c was thought to be the most Earth-like world known beyond our solar system. The equation said it was worth a measly $160. Mars fared better, priced at $14,000. And Earth? Our planet’s value emerged as nearly 5 quadrillion dollars. That’s about 100 times Earth’s yearly GDP, and perhaps, Laughlin thought, not a bad ballpark estimate for the total economic value of our world and the technological civilization it supports.
This video shows what various planets (Jupiter, Mars, etc.) would look like in the night sky if they orbited the Earth at the same distance as the Moon.
Early this week, I started seeing a little traffic to a post I wrote way back in March of 1999 called The new Zodiac.
An interesting calendrical tidbit: the Zodiac that everyone is familiar with today is actually based upon the movement of the sun through the constellations of 2500 years ago. Today, due to shifts in the earth’s rotation and orbit, the sun moves through 13 constellations, not just 12.
The thirteen constellation is called Ophiuchus. As I’m writing, Ophiuchus is the #1 trending topic on Twitter right now and there are dozens of news articles on the topic in outlets like Time, Huffington Post, and The Washington Post. Patient Zero of this most recent round of new Zodiac reporting is this January 9 Minneapolis Star-Tribune article in which the updated Zodiac is listed as:
Capricorn: Jan 20 - Feb 16
Aquarius: Feb 16 - Mar 11
Pisces: Mar 11 - Apr 18
Aries: Apr 18 - May 13
Taurus: May 13 - Jun 21
Gemini: Jun 21 - Jul 20
Cancer: Jul 20 - Aug 10
Leo: Aug 10 - Sept 16
Virgo: Sept 16 - Oct 30
Libra: Oct 30 - Nov 23
Scorpio: Nov 23 - Nov 29
Ophiuchus: Nov 29 - Dec 17
Sagittarius: Dec 17 - Jan 20
Aries: Apr 19 - May 14
Taurus: May 14 - Jun 21
Gemini: Jun 21 - Jul 21
Cancer: Jul 21 - Aug 11
Leo: Aug 11 - Sept 17
Virgo: Sept 17 - Oct 31
Libra: Oct 31 - Nov 21
Scorpio: Nov 21 - Nov 30
Ophiuchus: Nov 30 - Dec 18
Sagittarius: Dec 18 - Jan 21
Capricorn: Jan 21 - Feb 17
Aquarius: Feb 17 - Mar 12
Pisces: Mar 12 - Apr 19
Which calendar to believe? Who knows, but one thing is for sure: astrology remains a steamingpile of horseshit.
The object, called AFGL 3068, is a binary star, two stars in an 800-year orbit around one another. One of them is a red giant, a star near the end of its life. It’s blowing off massive amounts of dark dust, which is enveloping the pair and hiding them from view. But the system’s spin is spraying the material out like a water sprinkler head, causing this giant and delicate spiral pattern on the sky. And by giant, I mean giant: the entire structure is about 3 trillion kilometers (about 2 trillion miles) across.
Astronomer Francesco Pepe of the Geneva Observatory in Switzerland, who spoke Oct. 11 at an International Astronomical Union symposium on planetary systems, reported a new analysis using only HARPS data, but adding an extra 60 data points to the observations published in 2008. He and his colleagues could find no trace of the planet.
The paper reports the discovery of two new planets around the nearby red dwarf star Gliese 581. This brings the total number of known planets around this star to six, the most yet discovered in a planetary system other than our own solar system. Like our solar system, the planets around Gliese 581 have nearly circular orbits.
The most interesting of the two new planets is Gliese 581g, with a mass three to four times that of the Earth and an orbital period of just under 37 days. Its mass indicates that it is probably a rocky planet with a definite surface and that it has enough gravity to hold on to an atmosphere, according to Vogt.
Gliese 581, located 20 light years away from Earth in the constellation Libra, has a somewhat checkered history of habitable-planet claims. Two previously detected planets in the system lie at the edges of the habitable zone, one on the hot side (planet c) and one on the cold side (planet d). While some astronomers still think planet d may be habitable if it has a thick atmosphere with a strong greenhouse effect to warm it up, others are skeptical. The newly discovered planet g, however, lies right in the middle of the habitable zone.
Sam Arbesman’s prediction of May 2011 might have been too conservative. And 20 light years…that means we could send a signal there, and if someone of sufficient technological capability is there and listening, we could hear something back within our lifetime. Contact! (thx, jimray)
Back in July, Ben Terrett wrote a post about how many instances of the word “helvetica” set in unkerned 100 pt Helvetica it would take to go from the Earth to the Moon:
The distance to the moon is 385,000,000,000 mm. The size of an unkerned piece of normal cut Helvetica at 100pt is 136.23 mm. Therefore it would take 2,826,206,643.42 helveticas to get to the moon.
But let’s say you wanted to stretch one “helvetica” over the same distance…at what point size would you need to set it? The answer is 282.6 billion points. At that size, the “h” would be 44,600 miles tall, roughly 5.6 times as tall as the Earth. Here’s what that would look like:
The Earth is on the left and that little speck on the right side is the Moon. Here’s a close-up of the Earth and the “h”:
And if you wanted to put it yet another way, the Earth is set in 50.2 billion point type — Helvetically speaking — while the Moon is set in 13.7 billion point type. (thx, @brainpicker)
It’s not so much a video of a total solar eclipse (the recent one, as seen from Argentina on July 11) as a video of people watching a total solar eclipse.
The sound is key…the reaction is very much The Rapture/End Times/high on ecstasy. If I had a bucket list, seeing a total solar eclipse would be on it. (via bobulate)
A new Hubble discovery was announced today and it’s not for the faint of heart. At least, that is, if you care deeply about mysterious exoplanets 600 light years away.
WASP-12b is orbiting a sun-like yellow dwarf star 600 light-years away and it has such a tight orbit (of only 1.1 days) that it is being roasted to nearly 2,800 degrees Fahrenheit. This superheated state has caused the doomed exoplanet to puff up to nearly twice the size of Jupiter.
WASP-12b is in trouble and there’s no Willis/Affleck/Bay mission planned to save it. That said, it’s going to take about another 10 million years for WASP-12b to be totally eaten, so it has time to cross a few things off its bucket list.
Today’s wild space story is brought to us by Bad Astronomy:
We have a stellar cluster with thousands of times the Sun’s mass embedded in a nebula furiously cranking out newborn stars. A lot of them are near the physical upper limit of how big a star can get. The whole thing is only a couple of million years old, a fraction of the galaxy’s lifespan. One beefy star with 90 times the Sun’s mass got too close to some other stars, which summarily flung it out of the cluster at high speed, fast enough to cross the distance from the Earth to the Moon in an hour (it took Apollo three days). The star is barreling through the flotsam in that galaxy, its violent stellar wind carving out a bubble of gas that points right back to the scene of the crime, nearly 4 quadrillion kilometers and a million years behind it.
Click through to see the pictures and read a more thorough write up.
PS: 70% of the reason I linked to this is because of the title, “Rampaging cannonball star is rampaging.”
The Natural History Museum got a lot of hate mail from children when they demoted Pluto from planet to a resident of the Kuiper Belt, including this one from a fellow named Will:
One of the better lists out there: the top astronomy photos of the year. From the list, this is a more detailed view of the Martian landscape than we’re used to seeing:
In 2004, the Hubble Space Telescope took an image called the Hubble Ultra Deep Field; basically astronomers pointed the Hubble toward an “empty” part of space and took a long-exposure shot in the visible spectrum. What they found were thousands of far away galaxies from early in the development of the universe. Now the Hubble has peered even deeper into the universe in near-infrared and captured this image:
Each one of those little specks is an entire galaxy, some only 600 million years old. Here’s a zoomed-in section:
NASA announced that it has found pretty hard evidence of significant amounts of water on the Moon.
“We are ecstatic,” said Anthony Colaprete, LCROSS project scientist and principal investigator at NASA’s Ames Research Center in Moffett Field, Calif. “Multiple lines of evidence show water was present in both the high angle vapor plume and the ejecta curtain created by the LCROSS Centaur impact. The concentration and distribution of water and other substances requires further analysis, but it is safe to say Cabeus holds water.”
I don’t have to tell you about the implications here. Just think of how much you could sell authentic Moon bottled water for.
Update:Jonathan Crowe notes that the gear used to take these photos isn’t cheap.
The winner’s photo of the Horsehead Nebula (mpastro2001 also had a second photo in the top five) used a 12 1/2” Ritchey-Chretien telescope ($21,500) and an SBIG STL11000 camera ($7,195 and up) with an AO-L adaptive optics accessory ($1,795) on a Paramount ME mount ($14,500). Total cost for just the equipment mentioned here: $44,990.
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