He does say that it would not accelerate quickly. But it would have to accelerate quickly enough to reach escape velocity. So. Assuming it would work, it may have to be a hybrid. Interesting nonetheless.
Astronomy & Space Exploration
- Thread starter MrMarcello
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Rumours are that they've found signs of life on Venus
My brother says told me about this last night, says they released something early by mistake. Apparently they've detected phosphine, which some claim can only be produced biologically (sort of? It's on Jupiter already apparently, so I don't know. Maybe we don't know a way for it to appear on rocky planets). I've heard enough wild astronomy claims to remain skeptical, but who knows. If true, well...
Yes, they've been doing research into phosphine rigorously over the last decade before reaching the conclusion that it's impossible (to our current knowledge) for a rocky planet to produce phosphine without some form of life. Alien life on a planet as close as venus is very exciting, it more or less proves how common it will be throughout the universe.
Would be kinda funny for this to be legit, right after they've sent another billion dollar machine (with a helicopter!) to Mars. I know Venus is very hard to even exist on (to put it mildly), but it's still very unloved in exploration terms.
Anyone watched the new Netflix documentary about Challenger? Lucas saying he’d make the same decisions he made then all over again despite knowing it blew up and killed 7 people is one of the most extraordinary things I’ve ever seen.
What’s it called?
Challenger: The Final Flight. Definitely worth a watch.
Are these all supposed to be asteroids that have actually hit the earth ?
No, they're all still up there whizzing around!
I believe if they come in contact with earth they are meteorites rather than asteroids.
Cheers. I've been to the Meteor Crater in Arizona and it was absolutely massive.
I don't think this is correct. Meteoroids turn into meteors/meteorites, but asteroids just stay asteroids (as long as they don't split up into a bunch of meteorites).
I stand corrected. So what's the difference between meteoroids and asteroids? Does the first group orbit the earth and the latter the sun?
I think a meteoroid is mostly just a smaller piece of an asteroid, but I don't know how they are defined exactly.
A meteor is an asteroid that enters the atmosphere. If it physically survives to impact the surface it's a meteorite. So, asteroid in space, meteor as it burns through the atmosphere and a meteorite is the rock/iron that's left.
Edit: I've never heard of a meteoroid. Is that a variant on meteorite?
Edit 2: Checked. It's a small asteroid apparently.
Edit 3: So you're right and I'll just shut up.
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The differences are pretty straightforward, really.
* In the context of Earth...
- Cosmic dust = Astronomical object with a maximum diameter of ~100 µm. Super abundant in the cosmos, and sub-categorized by location (like interstellar dust).
- Micro-Meteoroid = Astronomical object with a minimum diameter of ~100 µm and maximum diameter of less than a speck of sand.
- Meteoroid = Astronomical object that is larger than a micro-meteoroid but with a maximum diameter of ~1 meter. These are found across the Solar System or in stable-ish orbits.
- Asteroid or Planetoid = Astronomical object with a minimum diameter of 1 meter to min-planet size (Ceres has a diameter of ~930 km). Typically found in the Asteroid Belt.
- Comet: Icy astronomical objects (largest recorded nuclear diameter = C/2002 VQ94 with ~100 km). Typically originate in the Kuiper Belt (short-period) or the Oort Cloud (long-period), and leave a coma trail because of wind and radiation when passing close to the Sun.
* In the context of Earth...
- Meteor = An astronomical object that enters the Earth's atmosphere and gets vaporized (shooting star effect).
- Meteorite = An astronomical object that survives vaporization and makes contact with the Earth's surface. Further sub-categorized into chondrite, achondrite, etc.
- Bolide = A meteor that burns exceptionally brightly in the atmosphere, and superbolide = bolide than is briefly 100 times brighter than the moon.
@Invictus
I am guessing that those diameters are likely equivalent diameters. Solid particles are typically non-spherical, so you obtain a characteristic of the particle, such as its area, volume, surface area, projected length etc and quote the diameter of a sphere with the equivalent characteristic.
I am guessing that those diameters are likely equivalent diameters. Solid particles are typically non-spherical, so you obtain a characteristic of the particle, such as its area, volume, surface area, projected length etc and quote the diameter of a sphere with the equivalent characteristic.
https://www.nature.com/articles/d41586-020-02717-3
This is stunning, one needs to stop for a minute and take in whats being seen here and marvel at this (EHT) achievement.
This is stunning, one needs to stop for a minute and take in whats being seen here and marvel at this (EHT) achievement.
That's so cool!
Its one of the few places on earth I really want to go to. The asteroid was only 46 meters in size!
Isn't it! We're very lucky in my opinion.
Can't wait for the Webb Telescope to launch. I'm certain we'll discover many wonderous things.
If it ever does!
Really hope so, would be such an achievement. Also an important tool for further exploration.
Its actually scary how massive the place is. There's a viewing observatory that allows you to actually stand on top of the crater from very high up. Apparently the NASA moon landing astronauts used the crater to simulate the moon's surface before the mission.
Did you go to the states primarily to go there?
Its taking forever isn't it. I'm so nervous something will go wrong, would be devastated.
A lot has been invested in the project so I'm confident it will be launched, hopefully without glitches.
Webb is gonna be responsible for some epic desktop backgrounds 
Me to i meant during and after launch.
Yeah, going to be a nervous launch and wait until we hopefully get to see the first images
Has anyone read Fred Hoyle "The nature of the universe"? I picked this book up for 10p from a university library but never got around to reading it. Is it any good?
I have not read that book. But Fred Hoyle was a firm believer in the universe being constant and never changing. And interestingly, when Hubble discovered that all of the galaxies were moving apart, leading to the conclusion that our universe was expanding and therefore must have had a beginning, it was Hoyle who is credited with the words Big Bang.
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Awesome.