- How did Leavitt's period-luminosity relation later enable Edwin Hubble to measure the scale of the universe?
Space Telescopes
Orbital observatories such as Hubble and JWST.
- What technologies today trace their imaging principles back to Boyle and Smith's 1969 sketch?
- Why does placing a telescope above Earth's atmosphere improve the images it can capture?
- What flaw caused Hubble's first images to come back blurry, and how large was the error in the mirror's shape?
- How was Hubble's vision corrected, and what major discoveries followed once it was fixed?
- What flaw in Hubble's mirror caused its early images to be blurred, and how was it caused?
- What did astronauts on STS-61 actually install during Hubble's 1993 servicing mission?
- How did the corrective optics fix Hubble's vision without replacing the flawed primary mirror?
- What scientific discoveries did Hubble go on to enable after the 1993 repair?
- What repair did astronauts make to the Hubble Space Telescope in December 1993, and how did it improve the 1994 Pluto images?
- What surface features could astronomers see on Pluto in Hubble's 1994 images?
- Why must X-ray telescopes operate above the Earth's atmosphere rather than on the ground?
- What other molecules have since been identified in exoplanet atmospheres using the technique pioneered on HD 209458 b?
- What technique did the Kalas team use with the Hubble Space Telescope to image a planet around Fomalhaut?
- What open question about TRAPPIST-1's planets is the James Webb Space Telescope now investigating?
- Why was JWST's deployment sequence so risky compared to a telescope in low Earth orbit?
- What is the L2 Lagrange point, and why does it put JWST beyond the reach of repair missions?
- Why is JWST's gold-beryllium mirror designed specifically to detect infrared light?
- Why did this detection matter more for what it proved about Webb's capabilities than about WASP-39 b itself?
- What five images did NASA release on 12 July 2022, and what did each one show?
- Why was there widespread anxiety about the Webb telescope's 344 single points of failure before launch?
- How did Gaia use the method of parallax to measure the precise distances to nearly two billion stars?
- Why was the L2 Lagrange point chosen as Gaia's observing position?
- What has Gaia's data revealed about the Milky Way's merger history and stellar streams?
- What ended Gaia's mission, and what happened to the spacecraft afterward?