Saturday, 21 May 2016
Thursday, 19 May 2016
10 things you should know before seeing 'The Martian'
On October 2 you can see actor Matt Damon "science the shit" out of Mars in a movie adaptation of "The Martian," a bestselling sci-fi novel by Andy Weir.
In the movie Damon plays the character Mark Watney, an astronaut who relies on engineering, chemistry, and botany to survive after his crewmates abandon him on Mars.
With so much science at every turn in the film, we think you'll enjoy it more with a little background knowledge. Thus, we've compiled this handy guide of essential Mars science, NASA trivia, and other key details to know before seeing film.
Keep scrolling, and don't worry; we've kept it as spoiler-free as possible.
1. How to get to Mars
The first scene in "The Martian" takes place on Mars, but how would humans even get there?
NASA estimates it would take about six to eight months with space travel technology we have now. In "The Martian," Watney and the rest of the crew use the fictional Hermes spacecraft to reach the red planet.
Hermes is "the most complex and expensive object ever built," astrophysicist Neil deGrasse Tyson says in a promotional video for the film.
On a real trip to Mars, we'll have to worry about the astronauts losing muscle mass and bone density while spending so much time in a microgravity environment. Space is also filled with dangerous cosmic radiation that can rip through a human's very DNA.
The Hermes has artificial gravity and a radiation shield to make the journey more comfortable for the crew. NASA is working on developing both of those things, but it has along way to go.
2. What it's like on Mars
Here's what Mars is like, according to NASA:
- Mars has a reddish-orange glow during the day from all the dust.
- Sunrises and sunsets appear blue because Mars has almost no atmosphere.
- One day or "sol" on Mars is a few minutes longer than an Earth day.
- One Martian year is nearly two Earth years. That's because Mars orbits the Sun much farther away than Earth, so it takes a lot longer for the red planet to complete one lap.
- The average surface temperature on Mars is a chilly minus-80 degrees Fahrenheit. But temperatures can swing from a low of about minus-195 degrees Fahrenheit in winter, to a comfortable 68 degrees Fahrenheit during the summer.
- Gravity on Mars is only about 40% that of Earth's, so you'd be 60% lighter (but not moon-bouncing light).
- Mars has barely any atmosphere — about 1% of the density of the cozy atmospheric blanket around Earth. That's hardly enough to protect the surface from dangerous space radiation.
- Dust storms can envelope the planet for days at a time.
It's a pretty inhospitable place. Good luck, Watney.
4. Keeping time on Mars
Mars is a completely different planet with it's own orbit and rotation, so days are measured differently there than on Earth.
One solar day on Mars, called a "sol," is about 40 minutes longer than an Earth day,according to the Planetary Society.
Watney measures the time he spends stranded on Mars in "sols" not days, which is how NASA keeps track of time on Mars in real life.
5. Shelter on Mars
The tent-like shelter Watney spends most of his time inside is called a "hab" — short for Mars Lander habitat.
NASA already has working prototypes of Mars habs, complete with oxygenators, water reclaimers, and airlocks to protect astronauts from the nearly airless, radiation-bombarded surface of Mars.
The space agency also recently hosted a competition to see who could design the best 3D-printable Mars hab. Some of the designs look really cool, and the winner might actually end up on the red planet some day.
Warning: The next slide has spoilers.
6. Farming on Mars
Warning: This slide has spoilers.
In "The Martian," Watney grows his own food by planting potato eyes in the ground. He fertilizes the plants with human waste and creates liquid water for the crop out of rocket fuel.
Given what we already know about Martian soil, there's no reason why this wouldn't work in real life, Bruce Bugbee, a botanist who's worked with NASA, told Tech Insider.
NASA is already making progress on farming in space. Earlier this year for the first time ever, astronauts on board the International Space Station tried some of the lettuce they grew in microgravity.
7. NASA's Plutonium batteries
Watney digs up a radioactive power source in "The Martian." It's called a radioisotope thermoelectric generator (RTG), and NASA relies on them for long-distance space missions.
RTGs are essentially batteries powered by radioactive plutonium-238. As the plutonium naturally decays, it generates heat, and the battery casing turns the escaping warmth into electricity.
Plutonium-238 is pretty much impossible to turn into a nuclear weapon, according to the Environmental Protection Agency. It's also not the kind of dangerous, skin-piercing radiation that humans have to worry about (unless it gets inside our lungs).
Still, a nuclear battery is dangerous to have around because it's very hot.
8. Communicating with Mars from Earth
Mars is so distant that it takes 15 to 20 minutes for a message sent from Earth to make it to there.
That's because a communication signal like a radio wave travels at the speed of light, and nothing can travel faster: Mars is about 140 million miles away from Earth, and the speed of light is about 671 million mph.
When you see the movie, see if you can tell if "The Martian" sticks to this immutable law of physics.
Warning: The next slide has spoilers.
9. A brief history of NASA's Mars spacecraft
Warning: This slide has spoilers.
In the movie, Watney has no way to communicate with NASA, so he finds and digs up Pathfinder — a spacecraft NASA really launched to Mars back in the 1990s. After a little hacking, he uses the robot to communicate with NASA using a replica back on Earth.
In the real world, NASA builds a working replica of every spacecraft in case something happens to it after launch. That way, engineers can troubleshoot problems and come up with fixes on Earth.
A real-life Pathfinder replica would need to be "turned on and dusted off," Green told Tech Insider, but it does exist. So NASA really could theoretically use it to communicate with a stranded Martian astronaut.
10. The completely true origin story of NASA's Jet Propulsion Lab
A key scene in "The Martian" claims NASA's Jet Propulsion Lab was founded after a few Caltech students accidentally blew up their dorm room.
Well, that story is true. It happened in the 1930s, when a group of graduate students known as "the rocket boys" blew up part of their building during a fueled rocket test. They were booted off the Caltech campus and started calling themselves the "Suicide Club," according to NASA.
Thankfully the club didn't live up to its name, and the rocket boys mastered building rockets. They eventually returned to Caltech, and were booted out again (we're assuming for more explosions) — but this time to their own laboratory. By the 1940s it had funding and an official name: the Jet Propulsion Lab.
And remember that the "The Martian" is a science fiction film — it's not going to get all the science right.
Tuesday, 17 May 2016
10 INTERESTING FACTS ABOUT MARS
Mars is a constant point of discussion for space explorers around the world. We’ve sent dozens of spacecraft there to study it. Some want to land astronauts on it. The planet is just far away to make that dream difficult, but just close enough to spark our imagination. So what are some of the most important things to learn about the Red Planet?
1. Mars Had Water In The Ancient Past:
We’ve been debating for centuries about whether Mars had life or not. In fact, the astronomer Percival Lowell misinterpreted observations of “canali” — the Italian word for channels — on the planet as evidence of alien-made canals. It turned out Lowell’s observations were hampered by poor telescope optics of his day, and the canals he saw were optical illusions. That said, several spacecraft have spotted other signs of ancient water — channels grooved in the terrain and rocks that only could have formed in the presence of water, for example.
2. Mars Has Frozen Water Today:
We’re very interested in the question of water because it implies habitability; simply put, life as we know it is more likely to exist with water there. In fact, the Curiosity rover’s mandate on Mars right now is to search for habitable environments (in the past or present). Mars has a thin atmosphere that does not allow water to flow or remain in large quantities on the surface, but we know for sure that there is ice at the poles — and possibly frosty locations elsewhere on the planet. The question is if the ice is capable of melting enough water in the summer long enough to support any microbes.
Mars Express Data from Mars South Pole. Credits: ESA/ Image Courtesy of F. Altieri (IFSI-INAF) and the OMEGA team
3. Mars Used To Have A Thicker Atmosphere:
For water to flow in the past, the Red Planet needs more atmosphere. So something must have changed in the past few billion years. What? It is thought that the Sun’s energy striking the atmosphere must have “stripped” the lighter forms of hydrogen from the top, scattering the molecules into space. Over long periods of time, this would lessen the amount of atmosphere near Mars. This question is being investigated in more detail with NASA’sMars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft.
4. Mars Has Some Extreme Highs And Lows In Terrain:
The surface gravity of Mars is only 37% of what you would find on Earth, which makes it possible for volcanoes to be taller without collapsing. This is why we have Olympus Mons, the tallest volcano known on a planet in the Solar System. It’s 16 miles (25 kilometers) high and its diameter is approximately the same as the state of Arizona, according to NASA. But Mars also has a deep and wide canyon known as Valles Marineris, after the spacecraft (Mariner 9) that discovered it. In some parts, the canyon is 4 miles (7 kilometers) deep. According to NASA, the valley is as wide as the United States and is about 20% of the Red Planet’s diameter.
5. Mars Has Two Moons – And One Of Them Is Doomed:
The planet has two asteroid-like moons called Phobos and Deimos. Because they have compositions that are similar to asteroids found elsewhere in the Solar System, according to NASA, most scientists believe the Red Planet’s gravity snatched the moons long ago and forced them into orbit. But in the life of the Solar System, Phobos has a pretty short lifetime. In about 30 million to 50 million years, Phobos is going to crash into Mars’ surface or rip apart because the tidal force of the planet will prove too much to resist.
6. We Have Pieces Of Mars On Earth:
Remember the low gravity on Mars that we talked about? In the past, the planet has been hit by large asteroids — just like Earth. Most of the debris fell back on the planet, but some of it was ejected into space. That sparked an incredible journey where the debris moved around the Solar System and in some cases, landed on Earth. The technical name for these meteorites is called SNC (Shergottites, Nakhlites, Chassignites — types of geologic composition). Gases trapped in some of these meteorites has been practically identical to what NASA’s Viking landers sampled on the Red Planet in the 1970s and 1980s.
Phobos, the larger of Mars’ two moons, with the Stickney crater seen on the right side. Credit: HiRISE, MRO, LPL (U. Arizona), NASA
7. Mars Would Kill An Unprotected Astronaut Quickly:
There are a lot of unpleasant scenarios for somebody who took of their helmet. First, Mars is usually pretty cold; its average temperature is -50 degrees Fahrenheit (-45 degrees Celsius) at the mid-latitudes. Second, it has practically no atmosphere. The air pressure on Mars is only 1% of what we have (on average) on the Earth’s surface. And third, even if it did have atmosphere, the composition is not compatible with the nitrogen-oxygen mix humans require. Specifically, Mars has about 95% carbon dioxide, 3% nitrogen, 1.6% argon and a few other elements in its atmosphere.
8. In The Early Space Age, We Thought Mars Was Like The Moon:
The early NASA probes that flew by the Red Planet all, coincidentally, happened to image spots on the planets that had craters. This led some scientists to (mistakenly) believe that Mars has an environment similar to the moon: cratered and practically unchanging. This all changed when Mariner 9 arrived at the planet for an orbital mission in November 1971 and discovered the planet engulfed in a global dust storm. What’s more, odd features were poking out above the dust — features that turned out to be dormant volcanoes. And as mentioned earlier, Mariner 9 found the vast Valles Marineris. It changed our view of the planet forever.
9. Mars Has Methane In Its Atmosphere:
Methane can be interpreted as a sign of biological activity — microbes emit it — or even of geologic activity. And active planets, it is thought, are more likely to have life on them. So the question of methane on Mars is one that scientists are trying to figure out. The consensus? There is no consensus. Telescopic observations have had wildly different measurements over the years, and few spacecraft have been designed to probe for the element in detail. The Curiosity rover has detected tenfold spikes in methane in its area, but we don’t know where it came from and why the fluctuations are happening.
10. Mars Is A Popular Spacecraft Destination:
There have been so many spacecraft that attempted a Martian mission that it’s hard to pick notable ones in a short article. NASA’s Vikings were the first landers in 1976; in fact, NASA is the only agency that has managed to land on the planet so far. Some of its other missions include Pathfinder-Sojourner (the first lander-rover combination) in 1997, the Mars Exploration Rovers Spirit and Opportunity in 2004, and the Curiosity rover of 2012. And this doesn’t even mention the fleet of orbiters that have mapped Mars over the years from the Soviet Union, NASA, the European Space Agency and India. And there are many more spacecraft to come in the next decade.
courtesy by : www,universetoday.com
Sunday, 15 May 2016
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