Week 3 was just me and Brendan since Andrei was gone for the first four days due to some summer internship. This week I focused on learning the major differences between space and ground based telescopes. The majority of my research focused on the major differences, but how with future projects NASA is working on improving major downsides to both space and ground based telescopes. Next week I’m working on researching some of those new projects and their advancements. I addressed this a little in my last post but one of the major advantages of ground based telescopes is that they are a lot cheaper. Ground-based telescopes cost about 10 to 20 times less than a comparable space telescope. The costliness of a space telescope such as the Hubble telescope includes the cost of materials, labor and launching it into space. [Picture of hubble]
Telescopes on Earth cost less because they don’t need to be launched into space, and the materials used in creating a ground based telescope are not as expensive. The two ground-based Gemini telescopes each cost about $100 million whereas the Hubble telescope cost U.S. taxpayers approximately $2 billion. [gemini telescopes]
Another big issue is maintenance of the telescope. Despite the quality of the workmanship, all telescopes will require some sort of maintenance. Engineers on Earth can easily maintain and fix malfunctions in ground based telescopes, whereas a team of astronauts and a costly space mission would have to be assembled for any failures in space telescopes. Ground-based telescopes have longer lifetimes because they can be repaired relatively easily.
On Earth, image quality of telescopes is worse than those in space. The elements and particles in the Earth’s atmosphere bend light so that images detected from ground based telescopes appear blurry. The atmosphere causes the apparent twinkling effect of stars, although stars don’t actually twinkle in space. Even with the invention of adaptive optics, a technique that reduces the effect of atmospheric interference on image quality, it still can’t reproduce the image clarity of space telescopes. Images taken by space telescopes like Hubble produce clearer images. [picture contrasting image clarity]
There are a few more major advantages/disadvantages of ground based telescopes but they revolve around similar ideas to those I explained. The week came to an end with the weekly Friday meeting which was extra special because one of the co-authors, Adam Burgasser, of the paper on the seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1 gave a short presentation on his paper. Unfortunately I didn’t get a picture with him but his paper discussed the news that NASA came out with on February 22nd. Also the day before the meeting there was a colloquium on exoplanets by Dr. Ruslan Belikov from the NASA Ames Research Center titled Beyond Kepler: Direct Imaging of Exoplanets. It was a great presentation and very useful because I had been doing some research on Direct Imaging and this helped expand my understanding of it.