A press convention was held on July 12 to current the primary pictures from the James Webb Area Telescope.
Along with 100 scientists from the Harvard-Smithsonian Heart for Astrophysics, I adopted the reside broadcast from the Phillips Auditorium of the identical middle.
We already had the Hubble telescope in area. Now we even have the James Webb.
Once you spend $9 billion on a brand new telescope, you don’t need it to be one bit higher than the previous one.
So why is Webb so significantly better than Hubble? That was the primary query that got here to me. My neighbors within the viewers responded very kindly.
- webb is larger. Hubble’s mild collector is 4 m2. Webb’s is 25 m2. So Webb collects 6.2 instances as a lot mild.
- Webb is healthier off. Hubble is orbiting the Earth, 550 km above our heads. Then the Earth itself hides a part of the sky from him. . As proven within the determine under (to not scale), Webb is situated on the L2 “Lagrange level”, about 1.5 million kilometers from Earth. The result’s that no a part of the sky is hidden from Webb.
- Hubble is delicate to seen mild. Webb is delicate to infrared mild. Here’s a very clear comparability of the two sensitivity ranges. Infrared mild penetrates finest by means of fuel and dirt discovered within the universe. Additionally, the redshift of very distant objects implies that their mild reaches us within the infrared. Lastly, “chilly” objects, reminiscent of exoplanets, are inclined to emit infrared mild.
- Infrared detection devices require a low and steady temperature. The L2 level gives this naturally. An Earth orbit doesn’t.
These strengths ought to make it potential research progress of the aforementioned goals:
- distant universe: first stars and galaxies shaped after the Large Bang, formation and evolution of galaxies.
- “chilly” targets: formation of stars and planets, extrasolar planetary methods.
In the meantime, the primary pictures are spectacular. My neighbors, who would have each motive to be fed up, since they spend their lives finding out these pictures, could not maintain again their ‘ohs’ and ‘ahs’ after they noticed the Webb pictures.
The loudest exclamations had been for the picture under. For comparability, I put the identical, taken by Hubble. I haven’t got so as to add the rest.
antoine brettProfessor of Physics on the College of Castilla-La Mancha (Spain).
1. If the Earth had been a basketball, Hubble could be 2 cm from its floor. Which means that nearly half of the sky is completely hidden from him.