10 Facts About the James Webb Space Telescope

It’s amazing what humans can accomplish when they stop blunting their intelligence with politics. And this one is truly remarkable—as in straight up mind boggling. Here are 10 facts about the James Webb Space Telescope (JWST) you should know to appreciate the marvel of modern science. Because this stuff can make your brain hurt, I used the site Big Think as a guide.

 

1

JWST was launched on December 25, 2021, from Kourou, French Guiana. It started its journey folded up inside an Ariane 5 rocket provided by the European Space Agency, parting ways with the rocket about 27 minutes after launch, later unfolding and heading to its final destination (see below) that was ultimately reached about one month later.

 

2

Regarding that final destination, it’s something called the L2 Lagrange point, around 940,000 miles away from Earth. Lagrange points are gravitationally stable points—this particular one allows for JWST to orbit the Sun in concert with Earth, facing away from the former and remaining on the nightside of the latter.

As a point of comparison, the well-known Hubble Space Telescope is about 340 miles from Earth in something called low-Earth orbit (and orbits the planet itself).

 

3

JWST is optimized to capture infrared light, a feature that allows the observation of extremely distant—and as the Big Bang Theory would have it, early—galaxies. Because the universe is expanding, what might have been emitted as visible light by such galaxies gets shifted to longer wavelengths—namely infrared—in a phenomenon called redshift.

As such, detecting infrared is key to studying stars and galaxies that were formed shortly after the Big Bang. In other words, if the Big Bang occurred 13.8 billion years ago, we’re talking about things that formed a couple hundred million years after that. And, of course, what we detect now is what was occurring at that time!

 

4

Because heat is a primary source of infrared, maintaining the telescope at a very cool temperature (under -370°F) is key to avoiding interference. The healthy distance from the Sun, Earth, and Moon (which is 250,000 miles from Earth) helps prevent the detection of heat/infrared from these entities. Similarly, a sizable sunshield protects the telescope from the heat that does make it to the neighborhood. Finally, a cooling system based on helium ensures that instruments do not detect infrared from the telescope itself.

 

5

As measured on Earth, JWST weighs about 14,300 lbs. Among many other things, that weight includes the aforementioned sunshield, a huge primary mirror (see below), and solar panels (which along with fuel provide power). Surprisingly, despite being around the size of a tennis court—compared to the school-bus-sized Hubble—JWST weighs only 58 percent of what Hubble weighed at launch.

 

6

The primary mirror of JWST has a diameter of about 21 feet (compared to Hubble’s 7.9 feet) and a light collection area of 273 square feet (compared to Hubble’s 43 square feet). Comprised of 18 separate segments made of beryllium and coated with gold (which is optimized for reflecting infrared), the primary mirror reflects light to a secondary mirror which then directs the light to various instruments for interpretation.

 

7

The anticipated lifetime of JWST was initially five to ten years depending upon the amount of fuel required to correct its initial course towards L2, maintain its orbit, and orient itself to particular targets. Given that the aforementioned launch went better than expected and resulted in significant fuel saving, that lifetime could have been extended to perhaps 20 years.

 

8

As you might imagine, this thing is not cheap. At the time of launch, it was estimated to cost close to $10 billion, a tad above the $1 billion that had been predicted in 1998 for a planned launch in 2007 (that got slightly delayed). Because of JWST’s distance from Earth, providing repairs is not practical, explaining the need to have everything perfect.

 

9

JWST has involved an inspiring collaboration between the National Aeronautics and Space Administration (NASA), the European Space Agency (ESA), and the Canadian Space Agency (CSA). Also involved are hundreds of other organizations such as universities and private contractors.

 

10

The majority of observation time for astronomers is allocated via an application process that is subjected to peer review.

 

James Webb, by the way, was a former NASA administrator best known for leading the Apollo programs that landed the first humans on the Moon. And he’d probably be horrified at how basic these facts about the James Webb Space Telescope are. What can I say—I’m just a blogger.