Author Question: Why are active galaxies assumed to be associated with galactic collisions? What will be an ideal ... (Read 51 times)

RRMR · **on:** Jul 27, 2018

Why are active galaxies assumed to be associated with galactic collisions?

What will be an ideal response?

Question 2

The NASA Curiosity rover exploring Mars carries a number of scientific instruments, including a spectrograph (a device for recording a spectrum), and a high intensity laser. On several occasions, Curiosity has fired its laser at the surface of a rock sample, while observing the process with a spectroscope. The laser is intense enough to vaporize the atoms on the surface of the sample into a hot, excited gas. Why is this a useful technique for the rover to employ?

What will be an ideal response?

deja · **Reply #1 on:** Jul 27, 2018

Answer to Question 1

Galactic collisions transfer mass between galaxies. This will cause extra matter to fall into the central black hole, triggering an eruption.

Answer to Question 2

The vaporized material will contain the elements present in the surface of the rock. Since it is a hot, excited gas, it will radiate an emission spectrum that can be recorded by the spectroscope. The emission lines can be analyzed to determine what chemical elements are present in the rock.

The technique is especially useful since it does not involve any physical contact with the rock. Only two simple tools are needed, and the rover may be able to use the technique to study samples that could not be reached by physical parts of the rover.