Saturday, September 28, 2013

This Saturday in Science is Feeling Spacy

Shamelessly cribbed from The Washington Post
The Voyager spacecraft, in flight since the disco era, is now passing out of our solar system.

Like geology and anthropology, the arc of space exploration is longer than the blinky, caffeine-driven attention span of our high speed nation.

In some ways that's a good thing as I suspect that long-term space-exploration projects probably move below the radar of those who would cut off our budget nose to spite our face.

In other ways, it's a bad thing because with such a methodical and plodding plot, it's difficult to build public support they way Kennedy did for the mission to the moon.

But despite the daily political waves, some science continues if only because it can no longer be stopped.

Case in point, the Voyager spacecraft.

When Voyager 1 was launched, K.C. and the Sunshine Band was more popular than his current gig at the Bethlehem Musikfest would suggest.

As The Washington Post reported on Sept. 12, Voyager 1 is now "more than 11 billion miles from Earth, has become the first man-made object to enter interstellar space."

More from the Post:
Scientists have long thought that there would be a boundary out there, somewhere, where the million-mile-per-hour “solar wind” of particles would give way abruptly to cooler, denser interstellar space, permeated by charged particles from around the galaxy.
That boundary, called the heliopause, turns out to be 11.3 billion miles from the sun, according to Voyager’s instruments and calculations, by Donald Gurnett, a University of Iowa physicist who has been working on the Voyager mission most of his adult life.
How NPR illustrated the two Voyager spacecraft near the
outer shell of the bubble around our solar system

Beyond the boundary, space is — perhaps counterintuitively — much denser with particles. There are 80,000 particles per cubic meter in the region where Voyager I is now, Gurnett said.
The sun’s hot ejecta — a plasma of charged particles — forms a vast bubble, known as the heliosphere. In the outer regions of the heliosphere, the particles are relatively few and far between, with just 1,000 particles per square meter in some regions, Gurnett said.
But the heliosphere has an edge. Voyager I’s epochal crossing of the boundary, into the cooler, denser plasma, took place on Aug. 25, 2012, according to the new report.
More from the Post:

The two Voyager spacecraft were launched in 1977. Voyager I flew by Jupiter and Saturn, the gravity of which helped slingshot the spacecraft toward the outer reaches of the solar system. Voyager I is now traveling at 38,000 miles per hour relative to the sun.
Voyager II flew near Jupiter and Saturn and then went on to pass by Uranus and Neptune. It is not quite as far from the sun as its sister spacecraft.
Although Voyager I is now in interstellar space, it hasn’t technically left the solar system. That’s because of the Oort cloud — a region of comets in orbit around the sun.
It will reach the inner edge of the Oort cloud in about 300 years, but will have stopped transmitting data.
The spacecraft draws power from the radioactive decay of Plutonium 238, and Stone thinks the dwindling power supply will force engineers to start turning off instruments in 2020. Voyager I probably will go dark by 2025.
Of course, as is the case with the Voyagers, nothing lasts for ever.

NASA has declared an end to Deep Impact, which in 2005 smashed a comet with a projectile to give scientists a peek of the interior. The spacecraft went on to rendezvous with two more comets.

This according to an Associated Press story which ran in The Mercury on Sept. 20:
Last month, engineers lost contact with Deep Impact and unsuccessfully tried to regain
Deep Impact completes its mission.
communications. The cause of the failure was unknown, but NASA suspects the spacecraft lost control, causing its antenna and solar panels to be pointed in the wrong direction.
University of Maryland scientists, who led the team, say the spacecraft lasted longer than they imagined and returned many discoveries about how comets formed.
During the mission, Deep Impact beamed back 500,000 images including of comet Ison, which could shine as bright as the moon when it makes a close approach in November.
Since there’s no way for ground controllers to talk to Deep Impact, the spacecraft will continue on its path around the sun until it runs out of fuel.

Of course some space exploration occurs in a chemistry lab.

Organic chemist Steven Benner made headlines last month when he declared that a chemical crucial to life may have been found in more abundance on Mars than here on earth.

In a lecture in Florence, Italy on Aug. 29, he "he challenged his fellow scientists to look hard at the evidence we have about how life began," according to this article in The New York Times.

"Depending on how you view that evidence, Dr. Benner argued, Mars might be a more likely place for life to have started than Earth. The best way to determine the actual answer, Dr. Benner argued, is to look for certain types of chemicals on both planets," The Times reported.

(You can get a copy of his lecture by clicking here. Warning, it's not free.)

Two chemicals, borate and molybdate help with the formation of RNA, the building blocks of DNA, and it would appear that at the time life began forming, those chemicals were found in much greater abundance on Mars than on Earth.

Maybe, we're all martians.....

On the other hand, the rovers now probing the surface of Mars have not been able to find any trace of methane, an element considered crucial to proving, or disproving, the existence of life.

As the Associated Press reported:
It's a finding that does not bode well for the possibility that microbes capable of producing the gas could be living below the planet’s surface, scientists said Thursday.
Since landing in Gale Crater last year, the car-size Curiosity rover has gulped Mars air and scanned it with a tiny laser in search of methane. On Earth, most of the gas is a byproduct of life, released when animals digest or plants decay.
Curiosity lacks the tools to directly hunt for simple life, past or present. But scientists had high hopes that the rover would inhale methane after orbiting spacecraft and Earth-based telescopes detected plumes of the gas several years ago.
Curiosity has yet to find any traces of methane, a sure sign of life,
but it has found water in the soil.
But on the other, other hand, just Thursday, it was announced that Curiosity has discovered water in fine-grained soil on the surface of Mars, NASA confirmed in a series of papers published in the journal Science.

Each cubic foot of Martian soil contains about two pints of liquid water, though the molecules are bound to other minerals in the soil.

According to The Guardian:
Curiosity made the measurement by scooping up a sample of the Martian dirt under its wheels, sieving it and dropping tiny samples into an oven in its belly, an instrument called Sample Analysis at Mars. "We heat [the soil] up to 835C and drive off all the volatiles and measure them," said Laurie Leshin, dean of science at Rensselaer Polytechnic Institute and lead author on the Science paper which confirmed the existence of water in the soil. "We have a very sensitive way to sniff those and we can detect the water and other things that are released."
Aside from water, the heated soil released sulphur dioxide, carbon dioxide and oxygen as the various minerals within it were decomposed as they warmed up.
The discovery of water is an important consideration for plans to send a manned mission to Mars. It is also considered a crucial discovery for those searching for life, or signs of life on Mars.

So the search goes on...

In the meantime, we also continue to study the moon.

On Sept. 5, Virginia's Wallop's Island entered the space race when it hosted the launch of a a five-stage Minotaur V, provided by Orbital Sciences, a Dulles-based company carrying the Lunar Atmosphere Dust and Environment Explorer.
As the name suggests, "plans call for the spacecraft to orbit the moon for 100 days on a science mission which includes collecting data on subjects such as the fragile, tenuous lunar atmosphere.

Eventually, according to the plans, the spacecraft , its fuel expended, will spiral down to the lunar surface of the moon," according to this article in The Washington Post.

And for those of us who wish to relive the spirit of adventure which permeated the Apollo space program, tip your hat to Mercury reporter Frank Otto who, despite not being alive at the time, found this link with the audio recordings of the Apollo 11 lunar landing.

I cannot embed the program, which is pretty cool, so you will have to go to this link, but I can tell you it's worth it.

The program not only shows you who is speaking, but offers an explanation of what each communication means.

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