Stories tagged Earth and Space Science

Jul
13
2012

Evolution timeline from 1882: This caricature of Darwin's theory appeared in the 1882 Punch Almanac. The recent evolution timeline created by Kyrk and Sezen is a bit of an improvement.
Evolution timeline from 1882: This caricature of Darwin's theory appeared in the 1882 Punch Almanac. The recent evolution timeline created by Kyrk and Sezen is a bit of an improvement.Courtesy Public domain via Wikipedia
This cool evolution timeline is really fascinating and fun to mess around with. I'm guessing Charles Darwin would agree it's a vast improvement over the one that appeared in Punch Almanac in1882 when he was still alive (see image at right). This new one was created by John Kyrk, a biology-trained artist in San Francisco in collaboration with Dr. Uzay Sezen, a plant biologist from the University of Georgia. The timeline is available in several languages and would be very useful in a classroom setting when studying evolution and paleontology.

The site is interactive and follows the evolution of our universe from the Big Bang to the present. You start it by clicking and sliding the red pyramid on the right. As you scroll across the timeline, various events in the history of the Universe, Solar System and ultimately, the Earth show up on the screen. All along, links also appear that either explain concepts or show examples of them. In the upper left hand corner is a menu linking you to several corollary Flash animations by Kyrk explaining cell biology and how RNA, DNA, cells, water, and other basic elements of life (including viruses) operate. Kyrk thinks animated illustrations are very useful in teaching and remembering ideas and concepts.

All the phases of Earth’s formation and development are covered in the evolution timeline, including the Late Heavy Bombardment, Snowball Earth, Cambrian Explosion, stromatolites, photosynthesis and iron formation. Once life begins to rise up, your computer screen will run amok with Earth’s diverse species populations from the one-celled animals, trilobites and fish to amphibians, reptiles, dinosaurs and mammals – the whole shooting match. All the major extinction events are shown, too.

The site also contains a link to this YouTube video version of someone else working the timeline so you can just sit back and watch how it happens, But I recommend working the interactive page yourself. A lot more happens and is available than the video allows you to see. Note that you’ll need Flash for it to run on your computer.

I wonder how Darwin would have reacted if he were able to see his theory illustrated in this way?

SOURCES
Evolution Timeline

Jun
22
2012

The Curiosity rover: It's going to look for signs of Mars' past habitability. Also, it's way bigger than the other Mars rovers; about 2,000 pounds, and the size of a compact car.
The Curiosity rover: It's going to look for signs of Mars' past habitability. Also, it's way bigger than the other Mars rovers; about 2,000 pounds, and the size of a compact car.Courtesy NASA JPL
Wait, who was I quoting in that headline? Me. I was quoting me, from when I described the upcoming Mars rover landing in my head as "pretty frickin' awesome." Or ... that was very nearly what I thought, but the specifics of what goes on in my brain pit are for adult ears only.

Which adult? This one. Me.

Anyway, NASA's Jet Propulsion Laboratory has produced a video about how the landing of the Mars rover Curiosity will go down, when the spacecraft carrying it reaches the Martian atmosphere on August 4. As you'll see when you watch the video below, there's dramatic music, scientists and engineers speaking dramatically, and dramatic flashing graphics. All very nice and of high production value, but it makes me want to say, "Hey, don't be dorks, dorks. Geez."

But I can't. Because it actually looks pretty awesome. The spacecraft is going to enter the atmosphere going 13,000 miles an hour, which will heat it up to about 1600 degrees. Then a giant, super tough parachute will shoot out, and slow it down to a couple hundred miles an hour. And then the capsule will break open (before it hits the ground), and another flying device will fall out, the "Sky Crane." The Sky Crane will use rockets to zoom away, and then hover above the surface of the planet. It will then lower the actual rover down on a cable. Once the rover touches down, the crane will blast off again, so it doesn't crash into the rover. Pretty amazing. Take a look:

August 4!

Jun
06
2012

The transit of Venus across the face of the Sun yesterday was a big attraction around Lake Calhoun in Minneapolis, MN. My brother and I set up on the east shore of the lake to watch the rare astronomical event, which started at 5:04pm and continued even after the Sun sank below the horizon. Swarms of people were at the lake enjoying the beautiful weather, and surprisingly many of them had a high level of interest in viewing the event. Luckily there were several telescopes, including my brother's Celestron, set up along the lake paths available to see it.

View through the Celestron: Venus (upper right) and several sunspots were visible on the Sun's surface.
View through the Celestron: Venus (upper right) and several sunspots were visible on the Sun's surface.Courtesy Mark Ryan

Everyone wants a look: Crowds gathered to get a view of the last transit of Venus until 2117.
Everyone wants a look: Crowds gathered to get a view of the last transit of Venus until 2117.Courtesy Mark Ryan

Another way to look at it: The Solarscope, which the owner said he had purchased in the early 1980s, is a cool viewing device that projected an image on the Sun and Venus.
Another way to look at it: The Solarscope, which the owner said he had purchased in the early 1980s, is a cool viewing device that projected an image on the Sun and Venus.Courtesy Mark Ryan

One final look: Venus was still in transit as the sun disappeared below the horizon.
One final look: Venus was still in transit as the sun disappeared below the horizon.Courtesy Mark Ryan

May
31
2012

Crash!: This illustration shows a stage in the predicted merger between our Milky Way galaxy and the neighboring Andromeda galaxy, as it will unfold over the next several billion years.
Crash!: This illustration shows a stage in the predicted merger between our Milky Way galaxy and the neighboring Andromeda galaxy, as it will unfold over the next several billion years.Courtesy NASA; ESA; Z. Levay and R. van der Marel, STScI; T. Hallas; and A. Mellinger
I think this is really interesting - below is straight from a release from NASA.

NASA astronomers announced Thursday they can now predict with certainty the next major cosmic event to affect our galaxy, sun, and solar system: the titanic collision of our Milky Way galaxy with the neighboring Andromeda galaxy.

The Milky Way is destined to get a major makeover during the encounter, which is predicted to happen four billion years from now. It is likely the sun will be flung into a new region of our galaxy, but our Earth and solar system are in no danger of being destroyed.

"Our findings are statistically consistent with a head-on collision between the Andromeda galaxy and our Milky Way galaxy," said Roeland van der Marel of the Space Telescope Science Institute (STScI) in Baltimore.

The solution came through painstaking NASA Hubble Space Telescope measurements of the motion of Andromeda, which also is known as M31. The galaxy is now 2.5 million light-years away, but it is inexorably
falling toward the Milky Way under the mutual pull of gravity between the two galaxies and the invisible dark matter that surrounds them both.

"After nearly a century of speculation about the future destiny of Andromeda and our Milky Way, we at last have a clear picture of how events will unfold over the coming billions of years," said Sangmo Tony Sohn of STScI.

The scenario is like a baseball batter watching an oncoming fastball. Although Andromeda is approaching us more than two thousand times faster, it will take 4 billion years before the strike.

Computer simulations derived from Hubble's data show that it will take an additional two billion years after the encounter for the interacting galaxies to completely merge under the tug of gravity and reshape into a single elliptical galaxy similar to the kind commonly seen in the local universe.

Although the galaxies will plow into each other, stars inside each galaxy are so far apart that they will not collide with other stars during the encounter. However, the stars will be thrown into different orbits around the new galactic center. Simulations show that our solar system will probably be tossed much farther from the galactic core than it is today.

To make matters more complicated, M31's small companion, the Triangulum galaxy, M33, will join in the collision and perhaps later merge with the M31/Milky Way pair. There is a small chance that M33 will hit the Milky Way first.

The universe is expanding and accelerating, and collisions between galaxies in close proximity to each other still happen because they are bound by the gravity of the dark matter surrounding them. The Hubble Space Telescope's deep views of the universe show such encounters between galaxies were more common in the past when the universe was smaller.

A century ago astronomers did not realize that M31 was a separate galaxy far beyond the stars of the Milky Way. Edwin Hubble measured its vast distance by uncovering a variable star that served as a "milepost marker."

Hubble went on to discover the expanding universe where galaxies are rushing away from us, but it has long been known that M31 is moving toward the Milky Way at about 250,000 miles per hour. That is fast enough to travel from here to the moon in one hour. The measurement was made using the Doppler effect, which is a change in frequency and wavelength of waves produced by a moving source relative to an observer, to measure how starlight in the galaxy has been compressed by Andromeda's motion toward us.

Previously, it was unknown whether the far-future encounter will be a miss, glancing blow, or head-on smashup. This depends on M31's tangential motion. Until now, astronomers had not been able to measure M31's sideways motion in the sky, despite attempts dating back more than a century. The Hubble Space Telescope team, led by van der Marel, conducted extraordinarily precise observations of the sideways motion of M31 that remove any doubt that it is destined to collide and merge with the Milky Way.

"This was accomplished by repeatedly observing select regions of the galaxy over a five- to seven-year period," said Jay Anderson of STScI.

"In the worst-case-scenario simulation, M31 slams into the Milky Way head-on and the stars are all scattered into different orbits," said Gurtina Besla of Columbia University in New York. "The stellar populations of both galaxies are jostled, and the Milky Way loses its flattened pancake shape with most of the stars on nearly circular orbits. The galaxies' cores merge, and the stars settle into randomized orbits to create an elliptical-shaped galaxy."

The space shuttle servicing missions to Hubble upgraded it with ever more-powerful cameras, which have given astronomers a long-enough time baseline to make the critical measurements needed to nail down
M31's motion. The Hubble observations and the consequences of the merger are reported in three papers that will appear in an upcoming issue of the Astrophysical Journal.

May
29
2012

Plastics!
Plastics!Courtesy IonE
This is a couple weeks old, but I just noticed that the University of Minnesota's Institute on the Environment (one of the Science Museum's partners on the Future Earth exhibit) has posted another "Big Question" video. These are short, fun videos that cover some of the challenges humans will be facing in the coming decades. This one is about plastics, and whether we can make them sustainable.

Anyway, here you are:

(And for more on the subject, check out Science Buzz posts on plastics, plastic, and sustainability.)

May
24
2012

So it's true?: Not necessarily the moon thing. The other part.
So it's true?: Not necessarily the moon thing. The other part.Courtesy Thomas Fowler and OZinOH
What does that title even mean?! I don’t know! Yakov Smirnoff stopped making jokes when I was a baby!

In Russia, phone dials you! In Russia, self-tanner applies you! In Russia, wife buys you! They’re all just meaningless words without the code!

Could it be that Russia has plans to establish a permanent base on the moon? Could that be? I mean, on one hand, my conception of Russia is more or less summed up by an imagined scene in which an old woman and a bear fight over a wilted cabbage. The old lady has a broom … but the bear wants the cabbage too! Does that sound like a space-colonizing nation?

Then again, the mighty USA has been hitching rides into space on Russian rockets for a while now, since we apparently decided that spaceships weren’t something we wanted to buy.

So who knows? Maybe Russia will put a permanent base on the moon. (Or maybe China or Japan will.) Maybe the US will go to an asteroid or to Mars. Maybe, in Russia, asteroid will go to you. Or maybe it’s all just astronaut pillow talk.

May
21
2012

Early stage of eclipse: the greenish tint is caused by shooting through welder's glass #14.
Early stage of eclipse: the greenish tint is caused by shooting through welder's glass #14.Courtesy Mark Ryan
I'm happy to report that the clouds cleared out just in time this weekend to watch the Sun and Moon do their little dance together in the western sky. I went to eastern shore Lake Calhoun in Minneapolis to watch, as did a number of other people. The best views took place later on as the sun lowered near the horizon. I brought along a piece of welder's glass #14 which attracted several curious passersby who ask if they could use it to view the sun. Other people brought along their own homemade devices to view the event. Overall, it turned into a rather nice little eclipse party. Viewing the eclipse: Two spectators use a an old printer box with a pinhole punched in it to watch the event.
Viewing the eclipse: Two spectators use a an old printer box with a pinhole punched in it to watch the event.Courtesy Mark Ryan

The eclipsed sun
The eclipsed sunCourtesy Mark Ryan

Closer view of the eclipse
Closer view of the eclipseCourtesy Mark Ryan

Double view: Binoculars worked well in projecting the crescent sun's image onto a white surface.
Double view: Binoculars worked well in projecting the crescent sun's image onto a white surface.Courtesy Mark Ryan
Another eclipse enthusiast checks out the view
Another eclipse enthusiast checks out the viewCourtesy Mark Ryan
Another view
Another viewCourtesy Mark Ryan
Look at that!: A family stopped by to view the eclipse through welder's glass.
Look at that!: A family stopped by to view the eclipse through welder's glass.Courtesy Mark Ryan
Viewing the eclipse: A helmet isn't necessary to view a solar eclipse, but proper eye protection against the sun's rays in essential.
Viewing the eclipse: A helmet isn't necessary to view a solar eclipse, but proper eye protection against the sun's rays in essential.Courtesy Mark Ryan
Makeshift viewing device: This woman made an eclipse viewer by poking a pinhole in a paper bag.
Makeshift viewing device: This woman made an eclipse viewer by poking a pinhole in a paper bag.Courtesy Mark Ryan
Eclipsed setting sun
Eclipsed setting sunCourtesy Mark Ryan
Kayak and eclipse
Kayak and eclipseCourtesy Mark Ryan

May
18
2012

Wheeeeeee!: I'm a computer generated mockup, but I feel like I'm flyiinggggggg!
Wheeeeeee!: I'm a computer generated mockup, but I feel like I'm flyiinggggggg!Courtesy FlyingSinger
The Flight of Dragons? Anyone? Anyone? 1982 Rankin/Bass? I don't know. I thought it was pretty dope when I was 5, but I felt that way about a lot of stuff.

Whoops! Got sidetracked there! What I meant to say is that the private spaceflight company, SpaceX, will be launching their Dragon capsule tomorrow, to rendezvous with the International Space Station. Assuming all goes well. (And let's be a glass-half-full crowd and just assume that, eh?)

The unmanned Dragon capsule will be hurled into the heavens on SpaceX's 2 stage Falcon 9 rocket. When it gets to the Space Station, it will do a practice docking run. (This whole thing is kind of a trial run, although Dragon will have some cargo for the astronauts aboard. Just for fun, I guess.)

You'll know if everything went off without a hitch, because your life will be changed forever, or something.

The Flight of Dragons!

May
18
2012

Annular solar eclipse sequence: Spain, 2005
Annular solar eclipse sequence: Spain, 2005Courtesy Cestomano
A rare opportunity for many of us astrogeeks takes place this Sunday (May 20, 2012) when a good portion of North America will experience an annular solar eclipse. The celestial mechanics start around 7pm CDT when the Moon begins to cross in front of the face of the Sun. Because the Moon's orbit is near its apogee with the Earth (that is at its farthest distance) it will appear smaller and won’t cover the entire solar disk (as it does in a total eclipse), but instead, a ring of sunlight will remain exposed at maximum eclipse. Here in Minnesota we won’t get that effect as only 80-90 of the sun will be covered from our vantage point, but since it starts so late in the day we should be able to watch the sun set in partial eclipse, which should look kind of cool. Let’s hope the weather cooperates. The East Coast of the US won’t see the eclipse because it will start there after sunset.

It’s best not to look directly at the Sun with the naked eye during this type of eclipse as even a sliver of sunlight can cause damage, but there are ways of viewing a solar eclipse safely.

My favorite phenomena during the partial phases of a solar eclipse are the odd shadows created by the leaves of trees and bushes. Each dappled shadow is an image of the crescent sun.

MORE INFO
NASA annular eclipse page
Mr. Eclipse info site

May
07
2012

Brontosaurs-a-chomping: The constant eating by herds of sauropods like these no doubt produced a constant flow of methane into the atmosphere.
Brontosaurs-a-chomping: The constant eating by herds of sauropods like these no doubt produced a constant flow of methane into the atmosphere.Courtesy Public domain
Imagine you’ve been transported back in time to the Late Jurassic and you’re sitting on a gently sloping hillside watching a large herd of the gigantic sauropod dinosaurs chowing down on tons of vegetation in the valley below. What’s the one thing you might need to worry about? The herd of sauropods suddenly stampeding the hillside? A truck-sized carnivore eyeing you from the shadows? Tiny burrowing mammals gnawing at your ankles? While all these scenarios would have been possible, the most likely worry would probably be (if you’re downwind anyway) getting inundated by a warm blast of dinosaur farts.

That’s right, dinosaur flatulence - tons of it - wafting over you like a huge, stinky old blanket. Ewww.

Researchers from Liverpool John Moore's University, the University of London, and the University of Glasgow have calculated that herds of sauropods, those tiny-headed ,long-necked, long-tailed herbivorous dinosaurs that populated the Jurassic landscape about 150 million years ago, would have been eating a lot of vegetation during their lifetimes and in the process releasing a tremendous amount of methane gas from their guts and into the Earth’s atmosphere. That's a lot of cheese-cutting.

In fact, writing in the journal Current Biology, Dr. David Wilkinson and his colleagues claimed that the amount of emission of methane just from the herbivorous dinosaur gassers would have been about the same amount being emitted from all sources today - 500-520 million tons each year. Methane is a greenhouse gas that can absorb the sun’s infrared energy, and heat up the atmosphere. The producers of methane today range from ruminant species such as cows, goats, and sheep, and from human activities such as natural gas drilling, but the effects on the environment could be similar – a warming of the atmosphere. Back in the Mesozoic, average temperatures were about 18 °F higher than today. Wilkinson and his colleagues suggest the dinosaur backfires could have been a big factor in the warming of the prehistoric environment, but admit it wouldn't have been the only source of the gas back then.

"There were other sources of methane in the Mesozoic so total methane level would probably have been much higher than now," Wilkinson said.

Wilkinson’s research interest lays not so much in the sauropods themselves but in the microscopic bacteria that once lined their guts. It was these microbes that converted the vegetable matter into energy and waste, including methane. Could that vast SBD Mesozoic methane source, as the researchers suggest, have been a big contributor to the warmer temperatures back then? Possibly. Or maybe it's just a lot of hot air.

SOURCE
BBC Nature News