Webb telescope launch: date, time and live broadcast | Top stories

If you wake up early enough on Saturday, you’ll be greeted by a science and engineering spectacle: the launch into orbit of the James Webb Space Telescope.

The telescope is a joint project of NASA, the European Space Agency and the Canadian Space Agency, and will be the most powerful observatory ever to be sent into space. Astronomers have waited decades as budgetary and technical delays have stalled the completion and launch of Webb.

But on Christmas morning, they and the rest of humanity will take one more step to see the spacecraft begin its science mission. Here is what you need to know.

When is the launch and how can I watch it?

The telescope is scheduled to take off at 7.20 a.m. EST on Saturday from a European-run spaceport in French Guiana, on the coast of South America. The launch window lasts 32 minutes, until 7:52 a.m., in case there are any last minute rocket checks or brief pauses in the countdown. A longer delay means the launch would be postponed to the same time on Sunday.

NASA, the telescope’s main funder, will host a live broadcast on its YouTube channel starting at 6 a.m., and on its main Twitter and Facebook accounts starting at the same time. Agency officials will comment on astronomers ahead of the launch. You can also register for a virtual launch event.

If you prefer to watch the launch in French or Spanish, the European Space Agency is also broadcasting the takeoff in those languages.

Why is the Webb telescope so important to scientists?

The Webb Telescope was designed to probe a crucial part of ancient cosmic history known to astronomers as the Dark Ages.

Cosmologists assume that the first stars appeared when the universe was only around 100 million years old. (Today, it is 13.8 billion years old.) The most distant and oldest galaxy seen by astronomers, using the Hubble Space Telescope, dates from when the universe was no longer old, 400 million years after the Big Bang. What happened during those 300 million years that the universe took a luminous flight, how the Big Bang turned into a sky full of constellations and life, is a mystery.

The telescope will also help astronomers better study supermassive black holes in the center of galaxies and planets orbiting other stars in our galaxy.

To carry out these scientific observations, the Webb telescope relies on a primary mirror 6.5 meters in diameter, compared to 2.4 meters for the Hubble mirror. This gives it about seven times the light gathering capacity and therefore the ability to see further into the past.

Another crucial difference is that it is equipped with cameras and other instruments sensitive to infrared radiation, or “heat.” The expansion of the universe causes light that would normally be in visible wavelengths to travel to longer infrared wavelengths normally invisible to human eyes.

Engineers had to invent 10 new technologies along the way to make the telescope more sensitive than the Hubble. Overly optimistic schedule projections, occasional development crashes and disorganized cost reports have dragged the schedule through 2021 and pushed the overall cost to $ 10 billion.

Why is the telescope launched from French Guiana?

The European Space Agency does not have an orbital launch site in any of its member countries on the European landmass. Instead, it’s usually launched from a spaceport in Kourou, French Guiana.

The use of the Kourou launch site is part of the consortium’s € 300 million contribution to the Webb mission. NASA signed an agreement with ESA to launch Webb on an Ariane 5 rocket from Arianespace, a French rocket manufacturer, in 2003.

Make your phone a personal planetarium.

To understand the observing powers of the James Webb Space Telescope and how it will help astronomers with their research, try these two augmented reality experiences in your own space with a smartphone connected to Instagram.

The first will show you where in space and time the Webb will be looking with a 3-D map of the observable universe. It traces some of the spacecraft’s earliest targets, including potentially Earth-like exoplanets and the earliest known galaxies. Try it out here on Instagram.

The second augmented reality experience shows how the Webb will get a visual boost from the power of the gravitational lens.

Place a virtual black hole in your space and observe how it behaves like a magnifying glass on your surroundings. This same technique will help astronomers study the early universe. Try it out here on Instagram.

Noah Pisner contributed reports.