Posted on 04/09/2018 8:38:33 AM PDT by Simon Green
For centuries, human beings have wondered about the possibility of other Earths orbiting distant stars. Perhaps some of these alien worlds would harbor strange forms of life or have unique and telling histories or futures. But it was only in 1995 that astronomers spotted the first planets orbiting sunlike stars outside of our solar system.
In the last decade, in particular, the number of planets known to orbit distant stars grew from under 100 to well over 2,000, with another 2,000 likely planets awaiting confirmation. Most of these new discoveries are due to a single endeavor—NASA's Kepler mission.
Kepler is a spacecraft housing a 1-meter telescope that illuminates a 95 megapixel digital camera the size of a cookie sheet. The instrument detected tiny variations in the brightness of 150,000 distant stars, looking for the telltale sign of a planet blocking a portion of the starlight as it transits across the telescope's line of sight. It's so sensitive that it could detect a fly buzzing around a single streetlight in Chicago from an orbit above the Earth. It can see stars shake and vibrate; it can see starspots and flares; and, in favorable situations, it can see planets as small as the moon.
Kepler's thousands of discoveries revolutionized our understanding of planets and planetary systems. Now, however, the spacecraft is nearly out of its hydrazine fuel and will end its fantastic life sometime in the next few months. Luckily for planet hunters, NASA's upcoming TESS mission is waiting in the wings and will take over the exoplanet search.
Kepler's history
The Kepler mission was conceived in the early 1980s by NASA scientist Bill Borucki, with later help from David Koch. At the time, there were no known planets outside of the solar system.
(Excerpt) Read more at phys.org ...
I love the gee whiz factor of space exploration and the pure science is valuable for our nation. Yet how are we going to pay for it?
I am really skeptical of this method.
First, it requires the planets to be on a plane directly in line with earth. What are the chances of all the so called planets being in such perfect alignment with earth?
Second, it requires the planet to cross the star in the short time frame we are watching.
Third, what it that star had a huge sun spot appear, resulting in a temporary drop in light. Would that be counted as a planet?
1. Yup. There are far more than we can detect with this method. Since we can’t get them all, why bother? This by-the-way is a terrible dating strategy...
2. Yup. We have to look to see them.
3. Nope. The dimming has to repeat on a regular schedule to count.
https://nypost.com/2018/10/30/nasas-kepler-telescope-officially-declared-dead/
Already well past its expected lifetime, the 9 1/2-year-old Kepler had been running low on fuel for months. Its ability to point at distant stars and identify possible alien worlds worsened dramatically at the beginning of October, but flight controllers still managed to retrieve its latest observations. The telescope has now gone silent, its fuel tank empty.
Dawn Is Dead: NASA’s Pioneering Asteroid-Belt Mission Runs Out of Fuel
https://www.space.com/42322-nasa-dawn-mission-ceres-vesta-ends.html
This topic was posted , thanks for posting it, thanks for reading it. I'm enjoying my end of the year check for missed topics.
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