Apophis; What would YOU do?

[Benjamin]

http://www.guardian.co.uk/space/article/0,14493,1660485,00.html

 

Above is a link to some of the intel on the "Apophis" rock. More info can be gleaned from the previous thread, if one wants it, or by checking out the article.

 

Now, everyone seems very excited about the idea of this asteroid passing close enough to see it (One my highschool science videos claimed it would pass closer than the moon). The problem is, it just might hit us. The effect might not be cataclysmic, but it would be kindasorta be like a kick in mother earth's testicles.

 

This is a somewhat theoretical discussion. What would you do against this possible Armageddon?

 

And whoever it was that said ideas and beliefs have no place in a science forum is full of crap. The greatest ability of a scientist is his/her capability of thought.

 

Another thought: This asteroid is going to come closer than any rock of its size in most likely thousands of years. THIS IS AN OPPORTUNITY!!!

 

We have thirty years. My question is not whether we can divert it, but Can we CATCH it?

[Martin]

thanks.

interesting piece from the Guardian on it

here's the WikiP article

http://en.wikipedia.org/wiki/99942_Apophis

it gives the mass as around 20 million tonnes

and other details like its orbital period and how close it is expected to come

 

WikiP is never perfectly reliable, but this article seemed OK as far as i can tell.

 

your idea of "catching it" would be to establish a permanent base on it? mining it for materials to use in space?

or were you thinking of an idea where the orbit is changed in some way?

[Spyman]

1) The impact probability for April 13, 2036, is estimated at 1 in 45 000.

 

2) It is to small to cause any "Armageddon".

 

3) ESA’s Don Quijote mission is currently planned to try to nudge it away.

(If they choose Apophis as target.)

 

The other thread: http://www.scienceforums.net/forum/showthread.php?t=28193

[Benjamin]

Yes, but would it be possible to catch the asteroid? would it be safe to have such an object near earth, or would its gravity throw things out of wack?

 

By letting it pass by, are we letting an astounding scientific opportunity fade away?

 

And thank you for the extra links.

[Spyman]

What do you mean with catch, letting it hit Earth or put in orbit ?

 

It's gravity is neglectable compared to Earths.

 

It won't go very far after the pass, Apophis has an orbital period about the Sun of 323 days, and its path brings it across Earth's orbit twice on each passage around the Sun. Any scientific study can still be planned and done on the next pass, if wanted.

[Benjamin]

Slow it down, possibly put it into orbit, yes.

 

Much more detailed experiments could be done on this asteroid than any that have been done before. This is an object that could turn out to be the greatest resource to date about understanding our solarsystem and universe, and the formation of it.

 

What decent experiments could be conducted in 3 hundred some days on a rapidly moving asteroid? Honestly, we would get a few satellites on it at most. Better to have an orbital, tangible asteroid than a few recordings and experiments by a satellite.

[Spyman]

I hope you realize that Earth is also rapidly moving around the Sun "in 3 hundred some days"...

 

Apophis is not going anywhere, it orbits the Sun, there is NO time limit.

 

And we would still have to go up/down from Earth to reach it, if "catched" in Earth-orbit.

 

 

For a much lower price, a robotic mission, similar to Spirit & Opportunity on Mars, could be launched.

(Spirit have been on Mars since January 4, 2004 and Opportunity landed three weeks after.)

 

They still performs extensive geological analysis of Martian rocks and planetary surface features.

http://marsrovers.jpl.nasa.gov/home/

 

Thats a little more than a few recordings...

 

 

Here are 3 examples of other such robotic spacecraft missions, on their way right now:

 

Rosetta is a European Space Agency-led robotic spacecraft mission launched in 2004 intended to study the comet 67P/Churyumov-Gerasimenko. Rosetta consists of two main elements: the Rosetta space probe and the Philae lander. The probe is named after the Rosetta Stone, as it is hoped the mission will help unlock the secrets of how our solar system looked before planets formed. The lander is named after the Nile island Philae where an obelisk was found that helped decipher the Rosetta Stone.

http://en.wikipedia.org/wiki/Rosetta_%28spacecraft%29

 

New Horizons is a robotic spacecraft mission conducted by NASA. It is expected to be the first spacecraft to fly by and study the dwarf planet Pluto and its moons, Charon, Nix, and Hydra. NASA may also approve flybys of one or more other Kuiper Belt Objects.

New Horizons was successfully launched on January 19, 2006. After a flyby of Jupiter on 28 February, 2007, it is expected to arrive at Pluto in July 2015 before becoming the fifth spacecraft to leave the Solar System.

http://en.wikipedia.org/wiki/New_Horizons

 

Cassini–Huygens is a joint NASA/ESA/ASI robotic spacecraft mission currently studying the planet Saturn and its moons. The spacecraft consists of two main elements: the NASA Cassini orbiter, named after the Italian-French astronomer Giovanni Domenico Cassini, and the ESA Huygens probe, named after the Dutch astronomer, mathematician and physicist Christiaan Huygens. It was launched on October 15, 1997 and entered into orbit around Saturn on July 1, 2004. On December 25, 2004 the Huygens probe separated from the orbiter at approximately 02:00 UTC, as confirmed by the Jet Propulsion Laboratory. It reached Saturn's moon Titan on January 14, 2005, where it made an atmospheric descent to the surface and relayed scientific information. It is the first spacecraft to orbit Saturn and the fourth to visit Saturn.

http://en.wikipedia.org/wiki/Cassini%E2%80%93Huygens

 

 

EDIT: Links to Don Quijote:

 

Don Quijote is a proposed space probe under consideration by the European Space Agency, which would study the effects of impacting a spacecraft into an asteroid. The mission is intended to test whether a spacecraft could successfully deflect an asteroid on a collision course with Earth. The orbiter is being designed to last for seven years.

The mission is still in the planning stages with a launch expected in 2011.

http://en.wikipedia.org/wiki/Don_Quijote_%28space_probe%29

http://www.esa.int/SPECIALS/NEO/SEMZRZNVGJE_0.html

http://www.esa.int/esaCP/SEML9B8X9DE_index_0.html

http://www.esa.int/esaCP/SEM8SUB1S6F_index_0.html

[YT2095]

yeah, that`s similar to what I would want to do also, get some good 2 way instrumentation up there, fire out a net and then hitch a lift around the solar system to free

 

thus far all the reccy missions have been a bit One way, this we know will come back to us several times

 

if we had a quick release on the tether, we could even drop it back off to Earth again or sling shot it out into space in a new direction

[Jacques]

Here is a link to an applet that might interest some of you:

http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=apophis;orb=1;cov=0#orb

[Martin]

Here is a link to an applet that might interest some of you:

http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=apophis;orb=1;cov=0#orb

 

that's neat!

when you click on the double arrow >>

you get an animated picture of apophis in orbit together with mars, earth

venus, mercury

 

Jacques, do you have anything special about the DAWN mission to CERES and Vesta?

it would be nice to have some resources about Ceres.

[Jacques]

There is a search on for the JPL Small-Body Database Browser, enter Ceres and you get:

http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=ceres;orb=1;cov=0#orb

You need to click on show orbit diagram. This applet use 2 body method to calculate the orbit.

A simple google :

http://dawn.jpl.nasa.gov/

[Martin]

Jacques, thanks for the Ceres stuff.

 

In case anyone is interested here is the WikiP on her

http://en.wikipedia.org/wiki/Ceres_(dwarf_planet)

Look at the cutaway diagram showing the ice mantle (60-120 km thick)

 

I believe that in the inner solar system Ceres is the most interesting body to develop. It is not just some dry rock---if current models are correct it has a huge amount of water in the form of ice.

That means it has available reaction mass (propellant).

 

Also you can hollow down into ice and make habitats (instead of bringing huts from home).

 

I see that Ceres is now classified as a "dwarf planet" instead of an asteroid. Just because it happens to be in the asteroid belt doesn't mean it should be called an asteroid, apparently.

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Benjamin,

You focused on Apophis the idea that we might CATCH it. In practical terms (since changing orbits is enormously time-consuming and expensive---and depending on the methods and circumstances can be risky) what that really means I think is to develop and UTILIZE.

 

Just to get some perspective, you might compare Apophis and Ceres as targets for development.

 

Mars appears to be largely dry and it has so much gravity that it is costly to boost stuff up off the surface. Even if you could find water under the surface it would be expensive to boost it into orbit and break it free of mars.

 

Ceres seems to be the first thing out beyond Mars that is really rich in propellant. Reaction mass is a strategic limiting factor in space logistics. Ion propulsion (e.g. using Xe or Hg) complicates the options and introduces some tradeoffs, but ultimately IMO doesn't change the basics in a qualitative sense.

 

An agency on Ceres with a source of energy (nuclear or solar) would be in a position to ship water to pretty much any destination in the inner solar system.

 

that is, assuming the current geological picture of the dwarf planet is correct:-)

 

The WikiP article says the orbit period is 4.6 years and the perihelion distance from the sun is 2.54 AU. It is only 2.5 - 3.0 times farther from sun than we are.

 

So might be good to keep it in mind as a benchmark target for development when you think about other projects.

 

The DAWN probe to Ceres took off yesterday 27 September 2007

[DrDNA]

http://www.guardian.co.uk/space/article/0,14493,1660485,00.html

This is a somewhat theoretical discussion. What would you do against this possible Armageddon?

 

Stock up on ammunition.

[Spyman]

Here is a popular science article, for those interested:

 

Dawn is now headed for a February 2009 swing past Mars before reaching its first space rock target, the bright and rocky asteroid Vesta, in August 2011. The probe's novel Xenon ion propulsion system is expected to guide it into orbit around Vesta for almost a year, then send it off toward the icy dwarf planet Ceres -- the largest space rock in the asteroid belt -- for a February 2015 rendezvous.

http://www.space.com/missionlaunches/070927_dawn_healthupdate.html

 

 

There are some indications that the surface of Ceres is relatively warm and that it may have a tenuous atmosphere and frost. The maximum temperature with the Sun overhead was estimated from measurements to be 235 K (about -38°C) on May 5, 1991.Taking into account also the heliocentric distance at the time, this gives an estimated maximum of ~239 K at perihelion.

A study led by Peter Thomas of Cornell University suggests that Ceres has a differentiated interior:

observations coupled with computer models suggest the presence of a rocky core overlain with an icy mantle. This mantle of thickness from 120 to 60 km could contain 200 million cubic kilometres of water, which is more than the amount of fresh water on the Earth.

http://en.wikipedia.org/wiki/Ceres_%28dwarf_planet%29

 

Based on observations made by the Hubble Space Telescope, astronomers think Ceres may harbor not only a thin atmosphere, but also a thick layer of water ice beneath its surface. If true, Ceres may boast nearly six times as much fresh water than is found on Earth.

"If we discover evidence of a subsurface ocean, than certainly it would be a high priority to go back and explore in more detail," said Mark Sykes, a Dawn co-investigator at the Planetary Science Institute in Tucson, Ariz.

http://www.space.com/scienceastronomy/070925_st_dawn_preview.html

 

Now you got me intrigued, Martin. - There seems to be a small possibility of life down there, below the ice...

[Ophiolite]

What would you do against this possible Armageddon?

In the unlikely event it is diverted, during a close approach, by enough to cause a later impact with the Earth then we need to more about its character. Diverting it from impact would certainly be technologically feasible, but we need to know if it is a rubble pile , a hunkg of iron, or a well compacted, unitary 'stone'. That means careful observation by multiple devices during its next close approach and , ideally, a rendezvous mission.

[Martin]

Now you got me intrigued,...might be life down there, below the ice...

 

I'm delighted that you are intrigued! I find Ceres really interesting too, so I am looking forward to whatever pictures and data the probe Dawn sends back.

 

the chance of life is always interesting and would be enormously important if found anywhere else in the solar system, but I don't count on that so much. I see Ceres more as an opportunity for development and utilization (whether or not some type of life has evolved in the ice).

 

I am glad it has been reclassified as a dwarf planet. After all, it round. Not just a lump of rock or the other things Ophiolite mentioned.

 

====================

Hi Ophiolite, glad to see you. I don't read the whole board, so I have missed your posts lately---havent seen any for a while.

 

You are an applied geologist I seem to recall (or that is one of the things you have done).

 

Tell me. Would a large air bubble, located one kilometer down in the ice, be geologically stable in Ceres gravity?

How to prevent the ceiling from melting, forming puddles on the floor which then freeze? The air would tend towards zero Celsius I suppose

 

Don't you dare dismiss the idea as silly.

[Spyman]

Composition of Apophis:

In research that could aid decisions about future asteroids on a collision course with Earth, MIT researchers have for the first time determined the composition of a near-Earth asteroid that has a very slight possibility of someday hitting our planet.

Binzel and his students were able to use both visible-light and infrared spectroscopy to show that Apophis is "a good match" for a rare type of meteorite, known as a type LL chondrite. These represent just 7 percent of the known meteorite falls on Earth, and are rich in the minerals pyroxene and olivine, which are also common on Earth.

 

"The beauty of having found a meteorite match for Apophis is that because we have laboratory measurements for the density and strength of these meteorites, we can infer many of the same properties for the asteroid Apophis itself," Binzel says.

http://www.spaceref.com/news/viewpr.html?pid=23786

 

 

Update on Dawn:

NASA's Dawn spacecraft bound for the solar system's two largest asteroids has aced the first test of its ion propulsion system, the space agency said.

The ion engines were tested at five different throttle levels and performed "flawlessly" according to Jon Brophy, the Dawn project's ion propulsion manager at JPL, in an official statement.

http://www.space.com/missionlaunches/071011-dawn-engineupdate.html

 

DAWN - Mission to 2 Asteroids, (old video): -> http://www.space.com/php/video/player.php?video_id=090707_dawn062607

(Leonard Nimoy narrates this preview of flight to Ceres and Vesta.)

[Mr Skeptic]

It seems the best idea for moving asteroids (other than bumping it) is to shine mirrors on it, creating a spot hot enough to vaporize. The vapor then pushes the asteroid, smoothly and gently so it won't break. At this point, we can hardly move a rock as big as Apophis, so I don't see us catching it. We're likely to send a tag-along though.

[Spyman]

I like the idea of painting it, using the Sun to gently and slowly push it, but it requires a lot of time.

Possible asteroid deflection strategies include "painting" the surface of the asteroid or focusing solar radiation onto the asteroid to alter the intensity of the Yarkovsky effect and so alter the orbit of the asteroid away from a collision with Earth.

http://en.wikipedia.org/wiki/Yarkovsky_effect

 

But of course, a spacecraft with large mirrors could be used several times, against multiple threats.

[Edtharan]

In the unlikely event it is diverted, during a close approach, by enough to cause a later impact with the Earth

A solution to this might be to divert it into the Moon. If it collides with the Moon, then it can no longer collide with Earth. Sure there will be some ejecta, but it will be smaller and the ejecta that did reach Earth would then likely burn up in the atmosphere (and being smaller, the impacts would be a lot smaller if they did hit Earth). However, a really large asteroid would not be able to be handled in this way and diverting it for a complete miss would be the only solution.