Space Fan News #73: Curiosity Lands Just Like Downtown; MyStar Game; Galactic Habitable Zones


Uploaded by tdarnell on 10.08.2012

Transcript:
Hello Space Fans and welcome to another edition of Space Fan News.
Well, unless you been living in an astronomical hole in the ground, you've heard that the
big news this week. The Mars rover Curiosity has safely landed on Mars.
So imagine this: you have a one ton vehicle headed for Mars, and to land safely, it needs
to go from 13,000 miles an hour to zero miles an hour in less than seven minutes.
If you haven't seen the video yet, JPL made an awesome one that went viral called 'Seven
Minutes of Terror' that you simply have to see. It does a great job of describing the
situation.
So, because Mars' atmosphere isn't thick enough to slow Curiosity down on its own, an elaborate
decent was planned: first the atmosphere would slow it down as much as it could and protect
Curiosity with a heat shield, which was soon ejected and a parachute deployed, slowing
it down some more.
But the thin atmosphere is a real problem, there just isn't that much there for the parachute
to grab hold of.
So after doing what it could, the parachute was released along with the back shell of
the spacecraft which then exposed a sky crane (!) with rockets that ignited slowing it down
further and it also slowly and gently lowered Curiosity down to the surface with cables.
Then, when it was safely on the ground, the sky crane flew itself out of the way to crash
somewhere well away from the rover.
Whew! What a ride! What made this so amazing was that if any one of those things didn't
work (heat shield failed, parachute didn't open, sky crane rockets don't fire, cables
break, any of it) then it was all over, the mission would have been lost.
But on Monday morning at 1:31 am Eastern Time, that didn't happen. All of it worked. just
like it was designed to, every single phase, and Curiosity is now on Mars, exactly where
it should be.
Just like downtown.
Here is a shot of Curiosity's heat shield falling to the surface after the atmospheric
entry phase is complete. These are taken from thumbnails of the Mars Decent Imager, or MARDI.
This was about one and a half minutes before touchdown.
Curiosity landed in Gale Crater, and here is some amazing footage taken from HIRISE,
the High Resolution Imaging Science Experiment in orbit. The resolution is so great in this
camera that it can actually resolve Curiosity on the surface.
This video also shows the aftermath of the seven minute descent. You can make out where
the heat shield went, the parachute and the sky crane. All well away from Curiosity.
OK, so now that it's on the ground, what makes Curiosity so special is that this is the first
rover since the Viking I and II landers in 1976 and 1977 to have an onboard chemistry
lab.
For the first time since Viking, we have the ability to take samples of Martian rocks and
soil to look for any signs of the building blocks of life or even any signs of life at
all.
In the coming years, Curiosity will head for a layered mountain, known as Mount Sharp,
inside Gale crater. The layers of this mountain contains minerals that form in water and was
selected by the Mars Reconnaissance Orbiter as a very promising site to look for early
building blocks of life.
On board, a suite of instruments named Sample Analysis at Mars will analyze samples of material
collected and delivered by the rover’s arm, along with atmospheric samples.
It includes a gas chromatograph, a mass spectrometer, and a tunable laser spectrometer with capabilities
to identify a wide range of organic compounds and determine the ratios of different isotopes
of key elements. Isotope ratios are clues to understanding the history of Mars’ atmosphere
and water.
It also has a mast camera, or Mastcam, which will take color images and color video footage
of the Martian terrain, including 10 frame per second high def videos.
And you know I'll be showing you those as they become available.
Never before has Mars been examined like this, so over the course of the next few years they
hope to learn whether life ever arose on Mars, characterize the climate and geology on Mars
and most importantly, prepare for human exploration of Mars.
I'll keep you posted.
Next, last week just before my well-received acting debut (don't worry I won't do that
again), I showed you a game developed with help here at the Institute called MyStar.
Many of you wanted to learn more about it so I've included a link to the website in
the description box. The concept is that you start out with these things called Starbux
and you can spend them to make stars in typical spiral galaxy.
You don't get much to start with and can really only create stars in pretty crappy spots in
the galaxy, but each star you create earns you more Starbux and as you gain more of them,
you can create better stars in better parts of the galaxy.
Every minute in the game is a million years, so if you create a red dwarf, it will take
a while to get any planets and they don't earn you much. I created a red dwarf and a
sun like star in the outer edges of the galaxy and by the next day I had enough Starbux to
make more stars.
You can only have a total of five stars, which I realize is limiting, but you need to understand,
this game was created with a sixty thousand dollar grant, they just got a million dollars
to make this into a Facebook game, so features will almost certainly be added.
So what I did was I made a couple of cheap stars in the outer rim and waited a few days
till they made me enough to buy a star in a decent area, then I was able to create planets.
I created an F0 class star in a star forming region bar the galactic habitable zone, and
after a couple of minutes, was able to create a gas giant. Then after about 10 minutes,
or 10 million years I was able to create terrestrial planets.
Problem was, I didn't wait long enough because it costs 3,000 starbux to make a terrestrial
planet and I didn't have enough, so I missed the window.
Please go play the game and let me know what you think.
My favorite thing about this game is that it exposes people to the concept of galactic
habitable zones. I've talked a lot about stars habitable zones on space fan news, but the
idea that galaxies have areas that are better for life is relatively new.
I'm making a video about this that goes into more depth, but the basic idea is that just
because every star in the galaxy can have a planet (remember we've talked about that
before), it doesn't mean each one can have life. Even if that planet is in the habitable
zone of the star.
There are many areas in the galaxy that are just not very hospitable: the edges of spiral
arms for example have rapid star formation and lots of supernovae. The center of the
galaxy is very high in radiation and gamma ray bursts, which can wipe out life on a planet.
These areas among others, have a high probability of wiping out many instances of life that
did manage to make it.
The current thinking is that the Milky Way's habitable zone is a torus about 30 light years
in diameter around the center, you can see that depicted here in the MyStar game. And
of course, we're in it.
But, there are other model that have more complicated maps of the Milky Way's habitable
zones that aren't so simple. But I'll talk more about that in my video, so look for that
soon.
Well, that's it for this week space fans. Thank you for watching and as always, Keep
Looking Up!.