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Where Knowledge Junkies Get Their Fix
In yesterday’s new feature The Analogist, I mentioned Luna 15, the Soviet spacecraft which crashed into the Moon while Neil & Buzz were there. This sounded made up, but it actually happened.
Let’s use that as a jumping off point for another pick-up game of Show Off Your Smarts. This week’s episode focuses on space trivia. Impress us with your knowledge.
Comments (24)
Comment
Uranus rotates on a verticle axis (their “equator” runs North to South, not West to East like on Earth).
Also, all of the gas giants have rings, not just Saturn.
posted by Amy on 6-29-2007 at 1:14 pm
The tail of a comet is “blown” by solar wind. The tail will always face away from the sun, no matter what direction the comet is moving.
posted by Rebecka on 6-29-2007 at 1:16 pm
A single day on the planet Mercury is twice as long as its year.
posted by John on 6-29-2007 at 1:37 pm
Venus does not tilt as ti goes around the sunm so consequently it has not seasons,
Since Neptune’s discovery i 1846, it has made about three-quarterso of one revolution of the Sun
posted by Lindsey on 6-29-2007 at 1:50 pm
Wasn’t this picture on the cover of Third Eye Blind’s second album “Blue” ?
posted by Janet on 6-29-2007 at 1:50 pm
When Apollo 11’s Lunar Module blasted off the moon, it destroyed the American flag they had placed too close to the stage.
Apollo 17’s lunar blast was filmed. The camera was on the lunar surface. The cameraman was in Houston, however, and had to tilt the camera up 5 seconds in advance of the actual launch, due to the signal lag. He nailed it, capturing a lunar POV of the vehicle ascending.
posted by Johnny Cat on 6-29-2007 at 2:03 pm
The observable universe is around 93 billion light years in diameter (This is the OBSERVABLE universe….not the universe in total..which is unknown).
The age of the universe is about 13.7 billion years.
Those numbers don’t make sense to me either, but who am I to argue with the smarty-pants scientists that figured them out?
posted by Drew on 6-29-2007 at 2:40 pm
In the observable universe there are about
- 80 billion galaxies
- 3 to 5 x 10^22 stars
- 10^80 atoms (lower limit)
posted by Drew on 6-29-2007 at 2:44 pm
The surface of the sun is about 6000 degrees kelvin. The corona, or outer atmosphere, reaches more than a million degrees kelvin. No one knows how the corona can be hotter than the surface. Of course there are theories, but none satisfactorily answer the puzzle.
posted by thew on 6-29-2007 at 3:49 pm
In Soviet Russia, MOON crashes into YOU.
posted by BrendonD on 6-29-2007 at 4:09 pm
The planet Uranus is the only planet in our solar system who’s axis is actually on its side.
It also has a faint set of rings revolving around it (sideways, of course).
posted by heather on 6-29-2007 at 9:41 pm
The Sun is actually green (in the visual spectrum) we here on earth percieve it to be yellow in color because our atmosphere “splits” the blue photons before reaching the surface. That’s why the sky is “blue” and the Sun is “yellow!”
posted by Kathryn on 6-29-2007 at 10:23 pm
Kathryn: I thought the Sun was actually white, it just emits more light in the green wavelengths (but when all the wave lengths combine, we get white light). Hence the reason clouds are white (and not green).
?
posted by Eric on 6-30-2007 at 1:32 pm
Jupiter’s Great Red Spot sits in the South Tropical Zone and cuts into the South Equatorial Belt.
Lunar mountain ranges are mostly the rims of giant impacts (look at the way Montes Capatus, Appenninus, and Alpes “circle” Mare Imbrium).
posted by Eric on 6-30-2007 at 1:44 pm
The amount of time it takes the moon to rotate on its axis is exactly the amount of time it takes to complete an orbit around the Earth. Because of that, we on Earth see only one hemisphere of the moon. Only a select few have seen the other side in person; the rest of us must be content with photographs.
The first photographs of the far side of the moon were taken by the Soviet Luna 3 space probe in 1959. It wasn’t until 1968 during the Apollo 8 mission that human eyes first saw it in person. But the crew was so busy making sure their trajectory was just right — they wouldn’t crash into the moon nor be flung off into space — that they didn’t have much time to enjoy the view.
posted by Dave on 7-1-2007 at 9:33 am
If you dropped Saturn into an ocean large enough to contain it, it would float.
Some of Saturn’s moons help to mainitain gaps in its rings with gravity.
posted by jenni on 7-1-2007 at 11:14 am
Venus is the only planet with a retrograde rotation, that is, the direction it spins on it’s axis is opposite it’s orbital motion about the sun. This means that the sun rises in the west and sets in the east.
Venus reaches it’s closest to earth every 584 days. This is almost exactly 5 Venusian solar days. Astronomers have yet to discover if this is purely a coincidence.
posted by Andy on 7-1-2007 at 9:20 pm
Light-years are a measure of distance, not time.
Our solar system is about two-thirds out from the center of the galaxy.
There is complicated evidence that there is a blackhole in the center of the galaxy.
Blackhole do not suck things in, but the high gravitational pull will not allow even light to escape.
If you watched a friend enter a black hole, they would appear frozen in time.
posted by Sandra on 7-1-2007 at 10:35 pm
To follow up on Sandra & Drew’s comments:
The question is if the universe started with a single point mass and is “only” 13.7 billion years old, how could the diameter of the universe be 93 billion light years? It should at most be 27.4 billion light years across. It’s almost 3.5x too big.
posted by Jeff on 7-2-2007 at 7:05 am
The Moon is not a satellite of the earth.
As an object travels in a curved path, it has an acceleration vector toward the concave side of its arc of travel. The Moon has an acceleration vector directed toward the Earth as it circles monthly, and also has a vector directed at the Sun as it circles annually.
The Moon’s acceleration vector with respect to the Sun is larger than it’s vector toward the Earth, so even at a point in it’s orbit when it is between the Earth and Sun and moving “away” from the Sun W.R.T. Earth, it is still accelerating toward the Sun.
Thus the Moon should be said to orbit the Sun, not the Earth. The Earth and Moon are a true binary planet.
posted by Brett A. Sloan on 7-2-2007 at 8:29 am
Jeff….It doesn’t make sense to me either. But that’s the answer I got when I looked it up. There was an explanation that went with it but being mentally challenged it didn’t make much sense to me.
“The comoving distance from the Earth to the edge of the visible universe is about 46.5 billion light-years in any direction; this is the comoving radius of the visible universe. It is sometimes quoted as a diameter of 92.94 billion light-years[4]. Since the visible universe is a perfect sphere and space is roughly flat, this size corresponds to a comoving volume of about 4/3 x pi x R^3 = 1.4 x 10^32 ly^3
or 3.4×1080 cubic meters.
The figures quoted are distances now (in cosmological time), not distances at the time the light was emitted. For example, the cosmic microwave background radiation that we see right now was emitted about 13.7 billion years ago by matter that has, in the intervening time, condensed into galaxies. Those galaxies are now about 46 billion light-years from us, but at the time the light was emitted, that matter was only about 40 million light-years away from the matter that would eventually become the Earth. See comoving coordinates.
While it is commonly understood that nothing travels faster than light, it is a common misconception that the radius of the observable universe must therefore amount to only 13.7 billion light-years. This would make sense in the static spacetime of special relativity and the big bang being an explosion in this unchanging spacetime.”
Now if anyone can explain exactly what all that means to me then please go ahead.
posted by Drew on 7-2-2007 at 9:53 am
Most of Jupiter is hydrogen. The pressure inside the planet is so great, and the hydrogen is so compressed, that it is in a liquid state. This liquid hydrogen state creates superfluidity.
posted by Iain010100 on 7-2-2007 at 10:17 am
The superfluidity of Jupiter’s hydrogen core causes it to behave as a superconducting metal. Couple this with the fact that Jupiter spins on its axis several times an hour and the result is Jupiter’s unbelievably massive electromagnetic field.
In contrast, the EM field that protects us from solar radiation and charged particles is generated by a comparatively tiny amount of iron spinning relatively slowly.
posted by MikeDub on 7-2-2007 at 8:57 pm
Comets actually have three tails - the ion or plasma trail made of hot gas, the dust trail, and the neutral sodium ion trail. The plasma trail is pushed straight back by the solar wind, whereas the dust trail is composed of larger debris that curves slightly along the comet’s path. Neutral sodium trails were not discovered until the unusually brilliant Comet Hale-Bopp, but have since been found on all comets and are even straighter than the plasma trail.
As for the observable universe, unless something’s changed since my astronomy class last semester, we can only see out to about 15-16 billion light years. This is not to say that it isn’t possible that radiation from stars or events more distant than that might be reaching us, but only that we haven’t yet got the technology to detect it.
Drew:
Basically, in a special relativity environment such as our universe is generally accepted to be, nothing goes faster than light because infinite energy would be required to drive it forward. Since light always moves at the speed of light, units of time coupled to that speed are convenient measuring sticks around the cosmos. However, with stars or events that are farther away from us, the measurements begin to break down because the space that the light has been traveling through has been expanding. The current theory goes that spacetime is getting bigger all the time, creating space in all directions almost like a balloon being blown up.
The common 13.6 billion ly number comes from calculations on the cosmic background radiation working from the Big Bang theory, assuming that the radiation comes from that event and calculating how long it would take a blackbody emitter (something that radiates all frequencies of the electromagnetic spectrum evenly, like stars do) to cool down from the estimated trillions of degrees generated at the beginning of the universe. They got about 13.6 billion years, so that is now the accepted figure for the age of the universe.
Assuming that the universe started at about the same size as it is now, then we couldn’t see any farther than the age of the universe times the speed that our information travels at (in this case, the speed of light). However, the going theory is that the universe has been creating space fairly evenly all around for billions of years. Therefore, light that originated from matter that was at one time much closer to Earth than it is now could arrive here thousands or billions of years before light from its current position could.
Photons cemitted in the sun’s core take approximately one million years to reach the photosphere (surface layer of the sun). From there, they take only eight minutes to reach Earth.
The event horizon (point at which nothing can escape) of a black hole is smaller than the planet Earth for a three-solar-mass black hole (the most common size). It is thus almost impossible to get pulled into one unless one wanted to go there in the first place.
posted by sfs on 7-2-2007 at 11:37 pm