MYSTERY PLUME ON MARS?

On Friday, 20 February 2015 03:57:24 UTC-5, Martin Brown wrote:
On 20/02/2015 04:27, palsing wrote:
On Thursday, February 19, 2015 at 7:44:18 PM UTC-8, RichA wrote:
On Tuesday, 17 February 2015 23:03:43 UTC-5, palsing wrote:
http://www.space.com/28573-mystery-p...pr=17610706465

Looks like an impact that stirred up a huge quantity of dust.

Do you suppose that an impact plume could last 10 days?

It might.

The gravity is weak and thermal effects of an impactor on the planets
surface would release liquid water and CO2 from deep underground which
would take some time to escape. The telling observation would be to find
a new crater in about the right place to be plausible.

--
Regards,
Martin Brown

How many spacecraft are in orbit, that could likely produce a good image of this? Seems odd all we have are "long-range" views.

On Friday, February 20, 2015 at 6:25:08 PM UTC-8, RichA wrote:

Do you suppose that an impact plume could last 10 days?

How long does dust from volcanoes stay in Earth's atmosphere?

I don't know about volcanoes, but I read somewhere that a hit from a extinction-class impactor could raise a dust cloud on Earth that could obliterate the Sun for about 10 years, and it would be this fact that caused most of that extinction... but I have no idea about Mars' atmosphere, and how long the dust cloud would last there, its atmosphere is a lot thinner that Earth's.

On Friday, February 20, 2015 at 7:40:10 PM UTC-8, palsing wrote:
On Friday, February 20, 2015 at 6:25:08 PM UTC-8, RichA wrote:

Do you suppose that an impact plume could last 10 days?

How long does dust from volcanoes stay in Earth's atmosphere?

I don't know about volcanoes, but I read somewhere that a hit from a extinction-class impactor could raise a dust cloud on Earth that could obliterate the Sun for about 10 years, and it would be this fact that caused most of that extinction... but I have no idea about Mars' atmosphere, and how long the dust cloud would last there, its atmosphere is a lot thinner that Earth's.

Actually, I do remember that Mt. Pinatubo in 1991...

http://www.mountpinatubo.net/

.... affected our atmosphere for at least 2 years.

\Paul A

On Friday, 20 February 2015 09:57:24 UTC+1, Martin Brown wrote:

The gravity is weak and thermal effects of an impactor on the planets
surface would release liquid water and CO2 from deep underground which
would take some time to escape. The telling observation would be to find
a new crater in about the right place to be plausible.

--
Regards,
Martin Brown

It seems there has been a seismometer on Mars since Viking in 1976. Perhaps it lacks the sensitivity to pick up impactors? Or is unsuited to that purpose. With all the talk of a Martian expedition by humans it would seem essential to have solid risk assessment data for impacts. Isn't there a greater risk of Martian impacts due to the proximity of the asteroid belt? The Martian atmosphere offers very little in the way of friction braking for anything incoming. Does the surface imagery offer any clues to a steady rain of lethal material?

On 21/02/2015 03:44, palsing wrote:
On Friday, February 20, 2015 at 7:40:10 PM UTC-8, palsing wrote:
On Friday, February 20, 2015 at 6:25:08 PM UTC-8, RichA wrote:

Do you suppose that an impact plume could last 10 days?

How long does dust from volcanoes stay in Earth's atmosphere?

I don't know about volcanoes, but I read somewhere that a hit from a extinction-class impactor could raise a
dust cloud on Earth that could obliterate the Sun for about 10
years, and it would be this fact that caused
most of that extinction... but I have no idea about Mars'
atmosphere, and how long the dust cloud would last there,
its atmosphere is a lot thinner that Earth's.

Actually, I do remember that Mt. Pinatubo in 1991...

http://www.mountpinatubo.net/

... affected our atmosphere for at least 2 years.

Affected the atmosphere as in slightly redder sunsets and miniscule
average surface temperature decrease but the optically dense local cloud
above the volcano only persisted whilst the thing was actively erupting
and followed by the fall time of the particles in it.

Ten days is in the about the right ballpark for an impactor into frozen
rock causing local heating and steam explosions (or from vulcanism but
that is not thought to be possible on Mars today).

The Icelandic volcano under ice Eyjafjallokull shut down European
airspace for about a fortnight whilst it was at its most active.

http://en.wikipedia.org/wiki/2010_er...llaj%C3%B6kull

Once the bulk of the dust has settled the remaining fines do stay in the
atmosphere for a long time but have a limited effect.

--
Regards,
Martin Brown

On Saturday, February 21, 2015 at 2:58:08 AM UTC-5, Chris.B wrote:

It seems there has been a seismometer on Mars since Viking in 1976. Perhaps
it lacks the sensitivity to pick up impactors? Or is unsuited to that purpose.
With all the talk of a Martian expedition by humans it would seem essential to
have solid risk assessment data for impacts. Isn't there a greater risk of
Martian impacts due to the proximity of the asteroid belt? The Martian
atmosphere offers very little in the way of friction braking for anything
incoming. Does the surface imagery offer any clues to a steady rain of lethal
material?

The chances of getting hit by a meteoroid would be the LEAST of your worries.

Long duration stays on the Moon could help give us a handle on the bone loss problem and ways to mitigate that.

Shielding from radiation would be very tough so short transit times are essential.

Food is likely to degrade over the course of the mission, leading to malnutrition in various ways.

"Chris.B" wrote:
On Friday, 20 February 2015 09:57:24 UTC+1, Martin Brown wrote:

The gravity is weak and thermal effects of an impactor on the planets
surface would release liquid water and CO2 from deep underground which
would take some time to escape. The telling observation would be to find
a new crater in about the right place to be plausible.

--
Regards,
Martin Brown

It seems there has been a seismometer on Mars since Viking in 1976.
Perhaps it lacks the sensitivity to pick up impactors? Or is unsuited to
that purpose. With all the talk of a Martian expedition by humans it
would seem essential to have solid risk assessment data for impacts.
Isn't there a greater risk of Martian impacts due to the proximity of the
asteroid belt? The Martian atmosphere offers very little in the way of
friction braking for anything incoming. Does the surface imagery offer
any clues to a steady rain of lethal material?


New craters have been found many times. This is the biggest.

http://www.jpl.nasa.gov/news/news.php?release=2014-162

On Tuesday, 24 February 2015 11:57:04 UTC+1, Mike Collins wrote:

New craters have been found many times. This is the biggest.

http://www.jpl.nasa.gov/news/news.php?release=2014-162

It seems an awfully long way to go just to become a troglodyte.