The phrases above are describing what layer of our atmosphere?
A) actinosphere
B) exosphere
C) ionosphere
D) thermosphere

Fades into outer space

No clear upper boundary  

Not all scientists agree that it is part of atmosphere

The phrases above are describing B) exosphere layer of our atmosphere

Explanation:

The exosphere is the uppermost region of Earth's atmosphere as it gradually fades into the vacuum of space. Air in the exosphere is extremely thin - in many ways it is almost the same as the airless void of outer space.The exosphere is perfect for placing satellites as there is very little friction and they are able to orbit fairly easily without being disrupted. Most of the molecules that exist in the exosphere end up being pulled back into earth's lower atmospheric levels by gravity.The air in the exosphere is very thin, and is made up mostly of helium, and hydrogen. Traces of other gases such as atomic oxygen and carbon dioxide can also be found. The upper level of the exosphere is the farthest point from earth that is still affected by earth's gravity.The exosphere is an important atmospheric layer as it functions as a transition zone between the earth's atmosphere and outer space It is the layer in which we can find artificial satellites that carry out constant studies of the earth and outer space. It also acts as a transit zone towards outer space.

The correct answer is  b) 

Science27 of the most iconic, jaw-dropping photos of the earth and the moon from spacedave mosher  oct 1, 2018, 11: 13 am etnasa/flickrapollo 11 astronauts took this photo of earth on july 20, 1969.from the ground, earth looks like a boundless fertile plain that beckons to be explored and exploited.but astronauts would beg -  and even plead  - to differ."you realize that people often say, 'i hope to go to heaven when i die,'" jim lovell, an astronaut who flew on the apollo 8 and apollo 13 missions to the moon, previously  told business insider. "in reality, if you think about it, you go to heaven when you're born."lovell has seen first-hand that we live on a tiny rock hopelessly lost in the void. he's also quick to tell you it's the only one we've got - a  fragile spaceship  for more than 7 billion people: "you arrive on a planet that has the proper mass, has the gravity to contain water and an atmosphere, which are the very essentials for life. and you arrive on this planet that's orbiting a star just at the right distance - not too far to be too cold, or too close to be too hot - and just at the right distance to absorb that star's energy and then, with that energy, cause life to evolve here in the first place. in reality, you know, god has really given us a stage, just looking at where we were around the moon, a stage on which we perform. and how that play turns out is up to us, i guess."humanity has recorded photos of earth from hundreds, thousands, millions, and even billions of miles away, some of them taken by lovell himself.these images not only scientists study our dynamic world, but also understand how a habitable planet looks from afar, which aids the search for  more worlds. most importantly, however, the images underscore our peculiar existence on  a mote of cosmic dust.take a moment to ponder 27 of the most arresting images of earth that humankind has ever captured from space.a