NASA announced on Monday afternoon (Feb. 10) that it has picked SpaceX to launch Pandora, a 716-pound (325-kilogram) satellite designed to help scientists better understand how our understanding of exoplanets' atmospheres are affected by changes in their host stars. Launch is expected No Earlier Than (NET) "this fall."
Considering that the 716 lb figure is a small fraction of the lift capability of the Falcon 9, I'll SWAG that it'll be part of a ride share mission of some sort. Once in orbit...
...the satellite will observe at least 20 known transiting exoplanets — worlds that cross the face of their parent star from the telescope's perspective. It will observe these planets 10 separate times, staring at them for 24 hours on each occasion.
"The satellite will use an innovative 17-inch (45-centimeter)-wide all-aluminum telescope to simultaneously measure the visible and near-infrared brightness of the host star and obtain near-infrared spectra of the transiting planet," NASA officials said in Monday's statement.
This is much like the way the very first exoplanets were discovered in the early 1990s. When the planet transits (passes in front of) the star it orbits, that star dims proportional to the amount of the star's disk that gets blocked out (astronomers refer to this as occultation or being occulted). As the star's light reaches the telescopes here on Earth, they frequently measure the spectrum of the starlight. By measuring the spectrum when not occulted and comparing it to when the planet comes between us, the chemical composition of the planet's atmosphere can be deduced.
Artist's depiction of the drop in measured light as the planet (black circle) occults the star. The light curve is the bottom middle line with a big "notch" (dip in brightness) during the occultation. Image credit: NASA
Pandora will be seeking out planets with atmospheres dominated by hydrogen or water.
However, this process depends on the star itself. If the star has regions that are particularly dark or bright, much like sunspot groups or plages seen on our own Sun, they can cause the star’s spectrum to vary over time in ways that can mimic or suppress features in the planet’s spectrum.
Pandora aims to disentangle the star and planet spectra by monitoring the brightness of the exoplanet’s host star in visible light while simultaneously collecting infrared data. Together, these multiwavelength observations will provide constraints on the star’s spot coverage to separate the star’s spectrum from the planet’s.
All we need now is a superluminal drive. Maybe one of those Buzzard Ramjets that use a steerable magnetic field ahead of it, scooping up interstellar hydrogen and pinching it down in a magnetic pinch where it creates a fusion drive, a moderner take on the ram jet kind of like. An unlimited fuel source, so you can basically keep accelerating till your turnover point, reach fractions of the speed of light. Still take a long time getting to the nearest star systems.
ReplyDeleteI remember reading about that sort Ramjet approach back in what must have been the Apollo era. The big issue is still your last line, though: "Still take a long time getting to the nearest star systems." Assuming there's no (much) faster than light travel.
DeleteYears. And years. And unlike Star Trek's "subspace" communication, one you're out there, YOYO - "you're on your own." There's no communications back to home because that takes years each way, too. One way messages are about all that can happen. Generational travel? Hibernation during the voyage, but still with IVs or something to keep you alive?
"Bussard". The approach has been studied a lot since he came up with it, and there are serious issues to solve. For one thing, colliding with particles at high subliminal velocities, even in an engine's throat, produces a significant amount of radiation. And the amount of interstellar hydrogen is still a speculated quantity.
DeleteStill, if it isn't possible to get past the speed of light, we're not going to be doing a lot of interstellar exploration.
Got the Buzzard Ramjet from the author Larry Niven, its a prominent space drive in his early Known Space series of stories. Actually he portrays the ramjet in as scientific features as possible based on present day known physics. Like the magnetic field is deadly to cordite life, really complex how the manned section is designed, turn over is difficult, and shielding from the fusion section is critical. Thing in his stories is they have superb longevity, once humming along they require minimal care to run, its pretty well thought out and a pretty cool idea, not too far beyond present technology, so it gives a certain possible credible caveat to their use in his writing. In one story the pilot has hi-jacked one from a tyrannical State, reaching relativistic speeds over decades, he had to add in a cold sleep tech so the main character lives ling enough to get back to earth centuries later to find it almost unrecognizable, a good space opera/swashbuckler.
DeleteIts called A World Out Of Time, written in the 70's, before he wrote Ring World, just a superb yarn itself.
Speaking of human space presence, this is an excellent video regarding a company going full bore on private venture spacecstations. They have some truly serious in house tech and show quite a lot if how they are engineering and building almost everything in house. One of the best i have watched. Highly recommend it. https://m.youtube.com/watch?v=us_V_e0-NVs
DeleteI keep an eye out for stories about Vast, and did one here just short of two years ago (May of '23). Unfortunately, that video you linked to was longer than the time I had available to watch it today.
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