Editor's note: This post is affiliated with the Overheard on CNN.com series, a regular feature that examines interesting comments and thought-provoking conversations posted by the community.
Life, as we know it, needs certain conditions to exist. Readers yesterday had some strong opinions about searching for that life elsewhere, after NASA made an announcement about a new planet outside our solar system:
Editor's note: Meg Urry is the Israel Munson professor of physics and astronomy and chairwoman of the department of physics at Yale University. She is also the director of the Yale Center for Astronomy and Astrophysics. She previously worked as a senior astronomer at the Space Telescope Science Institute, which runs the Hubble Space Telescope for NASA. This piece was written in association with The Op-Ed Project, an organization seeking to expand the range of opinion voices to include more women.
Nearly everyone I meet has heard of the Hubble Space Telescope. Many have seen its beautiful images of the birthplace of new stars and planetary systems, or of the "gravitational lenses" that reveal a mysterious "dark matter" that dwarfs the amount of matter bound up in stars or galaxies.
This year's Nobel Prize in physics went to three scientists who used Hubble to detect the mysterious dark energy - a sort of fifth fundamental force, previously unknown - that we now think is causing the accelerated expansion of the universe.
Hubble pictures and the knowledge the HST generates have changed our view of the cosmos and reached nearly every schoolchild in America.
Chris Ferguson, a veteran of three space flights and commander of the final shuttle mission, plans to retire from NASA on December 9 and take a job in the private sector, NASA announced Monday.
Ferguson is a retired US Navy captain. He joined the astronaut corps in 1998 and flew his rookie mission aboard Atlantis (STS-115) in 2006. STS-115 was an assembly mission to the International Space Station. He visited ISS twice more, most recently during the final space shuttle mission. Overall, Ferguson has logged 40 days in space.
NASA Administrator Charlie Bolden says of Ferguson in a statement: "Chris has been a true leader at NASA, not just as a commander of the space shuttle, but also as an exemplary civil servant, a distinguished Navy officer and a good friend. I am confident he will succeed in his next career as he brings his skill and talents to new endeavors."
Kepler-22b is the first confirmed planet in the “habitable zone,” the area around a star where a planet could exist with liquid water on its surface, that has been discovered by NASA’s Kepler mission.
The planet’s radius is about 2.4 times that of the Earth. It is located about 600 light years away. Its orbital period is shorter than that of the Earth: a "year" on Kepler-22b is 290 days instead of 365.
There were two other planets confirmed this year by other projects in the habitable zone, but their stars are much cooler than our Sun, and their orbits are more like that of Venus or Mars, scientists say.
Black holes: They're the most destructive monsters in the universe. We already knew they can be powerfully massive. Now scientists say they've found the most massive ones yet, as reported in the journal Nature.
The mass of each is about 10 billion times the mass of our sun. The previous black hole record holder, first measured in 1977, has a mass of about 6 billion suns.
"On Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, United Launch Alliance's Delta II rocket carrying NASA's Kepler spacecraft rises through the exhaust cloud created by the firing of the rocket’s engines. Liftoff was on time at 10:49 p.m. EST on March 6, 2009.
Kepler is a space-borne telescope designed to search the nearby region of our galaxy for Earth-size planets orbiting in the habitable zone of stars like our sun. The habitable zone is the region around a star where temperatures permit water to be liquid on a planet's surface. The challenge for Kepler is to look at a large number of stars in order to statistically estimate the total number of Earth-size planets orbiting sun-like stars in the habitable zone. Kepler will survey more than 100,000 stars in our galaxy."Source: NASA