In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

[Q]: What is the area of expertise of scientists who want to measure radiance from vegetation canopies?, Context: Oxygen presents two spectrophotometric absorption bands peaking at the wavelengths 687 and 760 nm. Some remote sensing scientists have proposed using the measurement of the radiance coming from vegetation canopies in those bands to characterize plant health status from a satellite platform. This approach exploits the fact that in those bands it is possible to discriminate the vegetation's reflectance from its fluorescence, which is much weaker. The measurement is technically difficult owing to the low signal-to-noise ratio and the physical structure of vegetation; but it has been proposed as a possible method of monitoring the carbon cycle from satellites on a global scale.
[A]: remote sensing


[Q]: Who wanted Kip to play himself?, Context: In June 2006, Steven Spielberg announced he would direct a scientifically accurate film about "a group of explorers who travel through a worm hole and into another dimension", from a treatment by Kip Thorne and producer Lynda Obst. In January 2007, screenwriter Jonathan Nolan met with them to discuss adapting Obst and Thorne's treatment into a narrative screenplay. The screenwriter suggested the addition of a "time element" to the treatment's basic idea, which was welcomed by Obst and Thorne. In March of that year, Paramount hired Nolan, as well as scientists from Caltech, forming a workshop to adapt the treatment under the title Interstellar. The following July, Kip Thorne said there was a push by people for him to portray himself in the film. Spielberg later abandoned Interstellar, which was eventually directed by Christopher Nolan.
[A]: people


[Q]: What did the astronauts send back to earth?, Context: On December 21, 1968, Frank Borman, James Lovell, and William Anders became the first humans to ride the Saturn V rocket into space on Apollo 8. They also became the first to leave low-Earth orbit and go to another celestial body, and entered lunar orbit on December 24. They made ten orbits in twenty hours, and transmitted one of the most watched TV broadcasts in history, with their Christmas Eve program from lunar orbit, that concluded with a reading from the biblical Book of Genesis. Two and a half hours after the broadcast, they fired their engine to perform the first trans-Earth injection to leave lunar orbit and return to the Earth. Apollo 8 safely landed in the Pacific ocean on December 27, in NASA's first dawn splashdown and recovery.
[A]:
TV broadcasts