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Two temperate Earth-mass planets orbiting the nearby star GJ1002
- prideout 4y agoLooks like they analyzed two datasets: one captured by a telescope in Chile, the other in Spain. We don’t hear about ground based telescopes in the news, I wish they were covered more often.
- eesmith 4y agoFWIW, four days ago there was https://news.ycombinator.com/item?id=33936559 https://news.ycombinator.com/item?id=33936559 , "Yale device delivers data from ‘Hell Planet,’ leads astronomers to its orbit", from a device "installed at the Lowell Observatory’s Lowell Discovery Telescope in Arizona". Seven days ago was https://news.ycombinator.com/item?id=33866917 https://news.ycombinator.com/item?id=33866917 , "Bright flash is a black hole jet pointing at Earth, astronomers say", from observations at the Zwicky Transient Facility.
- whoiscroberts 4y agoI’ll be excited when I can see an image with enough resolution to make out coastal borders.
- rqtwteye 4y agoLet’s hope you will live for quite a while. I think seeing coastal is very far away.
- Fezzik 4y agoWith current technology it would take nearly 40,000 years to travel a single lightyear… I hope you’re patient. For perspective, Voyager 1 has been hurtling through space since 1977 and has travelled a measly .002324439 lightyears. The Universe is mind bogglingly big.
- whalesalad 4y agoThanks for the perspective, I was curious about this.
- Tepix 4y agoYou could use the sun as the lens of a telescope to resolve city-size details on exoplanets. Might be easier to go 500 AU than several light years.
- SturgeonsLaw 4y agoThat's incredible. How are the photons from the planet not entirely drowned out by those emanating from the sun?
- deleted 4y ago[deleted]
- robbiep 4y agoI don’t know anything specific about what the parent is proposing, but I imagine it is using the mass of the sun as a gravitational lens. Because of the solar radiation there isn’t really much sunlight (read:any) that is directly reflected to an observer peering on the edge of the sun.. light travels in straight lines. Basically, the way scientists used a solar eclipse to confirm the theory of relativity and gravitational lensing of stars ‘behind’ the sun to in front of it. Or like the way certain objects were lensed in the massive JWST shot that came out a couple months ago. But beyond that I know nothing
- avian 4y agoHere's the paper discussing this idea: https://arxiv.org/pdf/2002.11871.pdf https://arxiv.org/pdf/2002.11871.pdf
- wruza 4y agoThey take pictures at night when there’s no sunlight.
- Ralfp 4y agoMaybe we’ll live long enough to see the completion of either solar gravitational lensing telescope or earth atmospheric lensing one. Either will (theoretically) let us imagine the surface features on extrasolar planets.
- ravel-bar-foo 4y agoWhat is the focal distance of solar gravitational lensing?
- mturmon 4y agohttps://www.centauri-dreams.org/2022/07/22/solar-gravitational-lens-sailcraft-and-in-flight-assembly/ https://www.centauri-dreams.org/2022/07/22/solar-gravitation... About 500 AU but it’s a design decision.
- holoduke 4y agoand you have to move several millions of miles to focus on a different target. Worst case a 1000 AU.
- dotancohen 4y agoHere is an image of the shore of a lake on Titan, one of Saturn's moons: https://nssdc.gsfc.nasa.gov/planetary/titan/huygens_titan_06.jpg https://nssdc.gsfc.nasa.gov/planetary/titan/huygens_titan_06... The lake is not liquid water, rather liquid hydrocarbons! That image was captured from the Huygens lander, you can see more images here: https://nssdc.gsfc.nasa.gov/planetary/titan_images.html https://nssdc.gsfc.nasa.gov/planetary/titan_images.html
- akiselev 4y agoThe star system in question: https://en.m.wikipedia.org/wiki/Gliese_1002 https://en.m.wikipedia.org/wiki/Gliese_1002 Only 15.8 lightyears away. Unfortunately I can’t find an estimate for the age but it’s a main sequence red dwarf with under 0.35 solar masses which implies it can burn for much longer than our sun - on the order of trillions of years: https://en.m.wikipedia.org/wiki/Red_dwarf https://en.m.wikipedia.org/wiki/Red_dwarf
- vondur 4y agoAt warp factor 5 it's only 27 days away!
- akiselev 4y agoDo you want an HN flamewar? Cause that’s how you start an HN flamewar! :-) The warp factor table at [1] makes absolutely no sense. Enterprise (the show) warp 4.6: 90 light years in 4 days. Voyager warp 4.7: 10 light years in 3 weeks. Enterprise (the show) warp 5: 50 light years in 3 months. [1] https://memory-alpha.fandom.com/wiki/Warp_factor https://memory-alpha.fandom.com/wiki/Warp_factor
- deleted 4y ago[deleted]
- TheFattestNinja 4y agoI dont know anything but im guessing warp might then count as power rather than speed and ship mass/warpdynamics might account for diffs?
- akiselev 4y agoFrom that warp factor page: > Although formulas to calculate a relative speed from a warp factor have existed in the writer's guides, these were rarely used for reference in the episodes and films. They just winged it with the technobabble. They retconned it by explaining that it’s a relativistic measurement which take into account gravity wells and ship size. I.e. even warp factor 10 (infinite speed in Voyager) might not be enough to escape a black hole if it gets too close. Edit: the ENT/VOY comparison makes no sense even with the retcon IMO, how is warp 4.6 in a mid-22nd century ship an order of magnitude faster than warp 4.7 in a 24th century ship?
- pfdietz 4y agoRed dwarf stars take up to 100 million years to settle down to the main sequence. Before that time, they are more luminous. During that period, these planets would not have been habitable and may have lost their water to space. Red dwarfs also subject their planets in the putative habitable zone to much stronger stellar winds and flare radiation, which makes survival of their atmospheres problematic.
- splittingTimes 4y agoFrom the abstract: "The closeness of the host star to the Sun makes [it possible] for their atmosphere to be studied via high-contrast high-resolution spectroscopy." Hopefully they can follow-up soon with those measurements. That could bring clarify to your fundamental questions.
- pfdietz 4y agoIt's possible that such planets could have abiotic oxygen atmospheres, from water photolysed by intense UV radiation from the star. The hydrogen would escape to space. For that reason, even if oxygen (or ozone) is detected, it would not necessarily be a sign of life.
- nine_k 4y agoThe presence of abiotic oxygen could help develop oxygen-breathing life, the same way as abiotic sulfur gives rise to teeming spots of life on the bottom of Earth oceans [1]. [1]: https://en.wikipedia.org/wiki/Hydrothermal_vent_microbial_communities#Sulfur_Cycle https://en.wikipedia.org/wiki/Hydrothermal_vent_microbial_co...
- perihelions 4y agoAny concrete numbers on that? I'd speculate there'd only be trace amounts: solar photochemistry is pretty slow, and rock weathering eats up any free molecular oxygen. Not sure of the relative rates.
- moloch-hai 4y ago
- jupp0r 4y agoWould life on earth be possible with an orbital period of 20 days?
- ShredKazoo 4y agoWhy not? Orbital period seems like the sort of thing life can evolve to adapt to relatively easily.
- Ralfp 4y agoOrbital period in itself is just a number. Interesting variable is how does the climate on planet change during it. On Earth climate gets affected because of axial tilt of the planet, giving different hemisphere different amount of solar energy during a year (due to length of a day and Sun path on the sky). If those planets have little axial tilt and little variety in distance to their star, there should be little variety in climate on them.
- heja2009 4y agoSince it is tidally locked around a low mass star, axial tilt should be near 0 and seasons should not exist [1]. Tidally locked also means much higher temperature than the estimated average (231K or -42C for the hotter one) on the sunny side and much lower ones on the dark side. [1] https://en.wikipedia.org/wiki/Axial_tilt#Extrasolar_planets https://en.wikipedia.org/wiki/Axial_tilt#Extrasolar_planets
- jjk166 4y agoThere are other ways for a planet to become tidally locked, for example Mercury is in a 3:2 resonance with the Sun. And if there is an atmosphere or a sufficiently deep ocean then even for a 1:1 tidally locked planet the temperature gradient from the light to dark side won't be too extreme.
- naasking 4y agoSure, there would just be no seasons. Everyday would just be roughly the same temperature as every other day. If the orbit is very eccentric, maybe 3-4 days would be like a brisk fall day, and 3-4 days would be like a hot summer day, and the rest would all hover around that average.
- Exendroinient00 4y agoNothing new, there are plenty of similar planets discovered around red dwarfs. Unfortunately, there are none found around the g-type stars and that's where the copy of earth ultimately should be possible.
- tjmc 4y agoFor values of "nearby" approximately equal to 149,346,794,944,180 kms.
- sidlls 4y agoIt’s not even a rounding error at the scale of our own galaxy (not joking: the measurement error for the size of the galaxy is something like +/-3kLY). May as well be next door. 15 LY is very close.
- nine_k 4y agoWere it a larger star prone to flares, that would even be dangerously close for Earths life.
- someonewhocar3s 4y ago
- m3kw9 4y agoI asked chatGPT this. using the following sentence, tell me how big are the planets comparing to earth: “We report the discovery[rest of the paper]..” It gave me this: “ The two planets orbiting GJ~1002 have minimum masses of 1.08 and 1.36 Earth masses, respectively. This means they are roughly the same size as Earth.” Is this correct?
- carl_dr 4y agoI mean, you can literally check that yourself? But no, it's not strictly correct. The paper gives the masses as 1.08±0.13Me (minimum mass 0.95Me) and 1.36±0.17Me (minimum mass 1.19Me.)
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