physics - meteors, orbits, and gravity

what forms of energy does a meteor on a collision course with earth possess while in space?

thermal energy, kinetic energy, gpe

“the element that helped scientists track down the asteroid that helped cause the dinosaur extinction was Iridium. This is an element that is rare on Earth, but can be used to radioactively date fossils because of its long half life.” What did corgy miss?

iridium is not used for radiometric dating. kpg has lots of iridium which shows evidence of a large asteroid impact. It had to have come from outside because it is common in asteroids.

when the solar system formed, why did gas Giants form so far from the sun compared to the inner-planets, which are mostly rock and metallic

they form so far from the sun because once nuclear fusion began, the energy output caused the material spinning around it to move outward. more dense material (rocks/metals) moved less, and lower density material (gases) moved much further out.

most meteors/asteroids that are within the vicinity of earth’s orbit are of the Stony/metallic kind. what is the asteroid bennu, and why is it significantly different from a typical near Earth asteroid?

It is small and likely came from the asteroid belt. it a carbenous asteroid, being made of ice and carbon rich compounds

provide 2 specific reasons why bennu is of scientific interest

1) bennu’s composition can teach us about other carbonaceous asteroids

2) bennu has the potential to collide with Earth

compared to metals or rocky material, water is a very low density compound, whether in the liquid or solid state. what is the currently understood, most likely way that water became a part of the Earth’s surface?

After the earth had formed, current ideas of how water came to Earth involve the early planet being struck by asteroids similar to bennu.

If 1 half life goes by for a particular radioisotope, what is the percent likelihood it will have decayed?

50%

if 14 half lives go by for a particular radioisotope and it has still not decayed, what is the percent likelihood it will decay after the next life?

50%

contrast the Russian meteor and chixulub

russian meteor came out of asteroid belt, while chixilub came out of kuiper.

why does a crater form?

impact events, volcanic activity, or explosions

what happens after 2 half lives?

25% of the original material remains

radiometric dating is expressed as what?

the measurement of the ratio of parent radioactive isotopes to their stable daughter isotopes

Half life must be measured in millions of years, thousands of years, days, or all?

all

kpg boundary refers to the layer of earth where

high iridium amounts are found