Bright Explosion on the Moon
science.nasa.gov
Bright Explosion on the Moon
1–10 of 66 posts
Re: Bright Explosion on the Moon
#2And that ladies and gentlemen is why having an atmosphere is a very good thing.
Re: Bright Explosion on the Moon
#3I found the footnote particularly interesting:
"The Moon has no oxygen atmosphere, so how can something explode? Lunar meteors don't require oxygen or combustion to make themselves visible. They hit the ground with so much kinetic energy that even a pebble can make a crater several feet wide. The flash of light comes not from combustion but rather from the thermal glow of molten rock and hot vapors at the impact site."
Re: Bright Explosion on the Moon
#4Can someone explain to me why this would be bright? I understand that this should send up a fair amount of ejecta but wouldn't most of the light be just from a reflection of the sun off of the particles?
If so, this isn't much of an explosion - it's just the most significant impact we've seen so far. I guess explosion is more interesting to the every-man.
Re: Bright Explosion on the Moon
#5Can someone explain to me why this would be bright? I understand that this should send up a fair amount of ejecta but wouldn't most of the light be just from a reflection of the sun off of the particles? If so, this isn't much of an explosion - it's just the most significant impact we've seen so far. I guess explosion is more interesting to the every-man.
Read rkaplan's comment above. In short, it's hitting with so much energy that the force of the impact alone is enough to leave the rock glowing-hot.
Re: Bright Explosion on the Moon
#6Just wanted to say that I helped build this site. It's 2009/2010-era Django site built on feincms with a PostgreSQL backend.
Originally it was a Plone site but after a year we realized it was too hard to meet the deadlines of NASA VIPs. So we moved it to Django. Also, myself and the other developers have NEVER been happy with the flash on the front page. :P
Re: Bright Explosion on the Moon
#7Can someone explain to me why this would be bright? I understand that this should send up a fair amount of ejecta but wouldn't most of the light be just from a reflection of the sun off of the particles? If so, this isn't much of an explosion - it's just the most significant impact we've seen so far. I guess explosion is more interesting to the every-man.
The massive kinetic energy must be dissipated on impact. Some is consumed in displacing the material on the lunar surface. Some is converted into thermal energy, resulting in hot enough material to radiate energy in the visible spectrum.
Re: Bright Explosion on the Moon
#8And that ladies and gentlemen is why having an atmosphere is a very good thing.
I wonder if the meteorite that exploded in the atmosphere over Russia did more or less damage than if it had struck the earth intact.
Clearly Atmosphere makes a good shield for burning up the small meteorites - but I wonder if it exacerbates the damage from medium sized ones?
Re: Bright Explosion on the Moon
#9And that ladies and gentlemen is why having an atmosphere is a very good thing.
I wonder if the meteorite that exploded in the atmosphere over Russia did more or less damage than if it had struck the earth intact. Clearly Atmosphere makes a good shield for burning up the small meteorites - but I wonder if it exacerbates the damage from medium sized ones?
Had that impact hit the ground it would have released over 100 kilotons of energy. It would have been far, far more destructive and deadly.
Re: Bright Explosion on the Moon
#10Can someone explain to me why this would be bright? I understand that this should send up a fair amount of ejecta but wouldn't most of the light be just from a reflection of the sun off of the particles? If so, this isn't much of an explosion - it's just the most significant impact we've seen so far. I guess explosion is more interesting to the every-man.
The ejecta aren't tossed about due to recoil they are lifted out of the ground by an expanding sphere of vaporized rock. And that vaporized rock glows because it is superheated to thousands of degrees, that's what creates the bright flash.