gildings in this subreddit have paid for 7.80 months of server time

Help my relationship by fornewfriends7 in space

[–]jseyfer 569 points570 points  (0 children)

You know what’s funny though? She’ll ask me to come to Joanne’s with her, and inside I’m kicking and screaming, but outwardly I’m going to be generous and willing- to be a good friend. So we’ll get there and she’ll ask me my advice on a pattern or a color combination or whatever and I’m always 10/10! She’s like- “How do you always * know* all the right colors? Like- just now, how did you know that by adding that little bit of orange, it would off-set that brown so nicely?” And inwardly, I’m thinking- “We have such a great marriage. I love this woman so much. I hope I don’t find out at some point I’m gay and ruin everything.”

Stephen Hawking helped us create this show and today we’re releasing it for free. No paywall, ads or email address required to stream the series. by CuriosityStream in space

[–]CuriosityStream[S] 2973 points2974 points  (0 children)

Noted, we're adding subtitles within the next few hours. Glad you're enjoying the show.

Edit: Subtitles are up! Just click the CC button in the video player to active them. -Chris

Uranus was discovered on this day 237 years ago by British astronomer William Herschel. by hypsotaxie in space

[–]MisterDecember 447 points448 points  (0 children)

Here’s another interesting piece of information. Galileo Galilei invented the thermoscope which is the forerunner of the rectal thermometer.

Galileo also created the theory of heliocentric orbits by studying near planets like Mercury. This led to the discovery of further planets like Uranus.

So, this is a man who found two different ways to apply Mercury to Uranus.

Edit: Thanks for the gold, kind stranger!

I don't want to be anti science, but i am doubtful of dark matter and energy being exactly what we think they are. Are there any reputable competing theories? by Cadenca in space

[–]Senno_Ecto_Gammat 756 points757 points x3 (0 children)

Below is basically a historical approach to why we believe in dark matter. I will also cite this paper for the serious student who wants to read more, or who wants to check my claims agains the literature.

  1. In the early 1930s, a Dutch scientist named Jan Oort originally found that there are objects in galaxies that are moving faster than the escape velocity of the same galaxies (given the observed mass) and concluded there must be unobservable mass holding these objects in and published his theory in 1932.

    Evidence 1: Objects in galaxies often move faster than the escape velocities but don't actually escape.

  2. Zwicky, also in the 1930s, found that galaxies have much more kinetic energy than could be explained by the observed mass and concluded there must be some unobserved mass he called dark matter. (Zwicky then coined the term "dark matter")

    Evidence 2: Galaxies have more kinetic energy than "normal" matter alone would allow for.

  3. Vera Rubin then decided to study what are known as the 'rotation curves' of galaxies and found this plot. As you can see, the velocity away from the center is very different from what is predicted from the observed matter. She concluded that something like Zwickey's proposed dark matter was needed to explain this.

    Evidence 3: Galaxies rotate differently than "normal" matter alone would allow for.

  4. In 1979, D. Walsh et al. were among the first to detect gravitational lensing proposed by relativity. One problem: the amount light that is lensed is much greater than would be expected from the known observable matter. However, if you add the exact amount of dark matter that fixes the rotation curves above, you get the exact amount of expected gravitational lensing.

    Evidence 4: Galaxies bend light greater than "normal" matter alone would allow. And the "unseen" amount needed is the exact same amount that resolves 1-3 above.

  5. By this time people were taking dark matter seriously since there were independent ways of verifying the needed mass.

    MACHOs were proposed as solutions (which are basically normal stars that are just to faint to see from earth) but recent surveys have ruled this out because as our sensitivity for these objects increase, we don't see any "missing" stars that could explain the issue.

    Evidence 5: Our telescopes are orders of magnitude better than in the 30s. And the better we look then more it's confirmed that unseen "normal" matter is never going to solve the problem

  6. The ratio of deuterium to hydrogen in a material is known to be proportional to the density. The observed ratio in the universe was discovered to be inconsistent with only observed matter... but it was exactly what was predicted if you add the same dark mater to galaxies as the groups did above.

    Evidence 6: The deuterium to hydrogen ratio is completely independent of the evidences above and yet confirms the exact same amount of "missing" mass is needed.

  7. The cosmic microwave background's power spectrum is very sensitive to how much matter is in the universe. As this plot shows here, only if the observable matter is ~4% of the total energy budget can the data be explained.

    Evidence 7: Independent of all observations of stars and galaxies, light from the big bang also calls for the exact same amount of "missing" mass.

  8. This image may be hard to understand but it turns out that we can quantify the "shape" of how galaxies cluster with and without dark matter. The "splotchiness" of the clustering from these SDSS pictures match the dark matter prediction only.

    Evidence 8: Independent of how galaxies rotate, their kinetic energy, etc... is the question of how they cluster together. And observations of clustering confirm the necessity of vats of intermediate dark matter"

  9. One of the recent most convincing things was the bullet cluster as described here. We saw two galaxies collide where the "observed" matter actually underwent a collision but the gravitational lensing kept moving un-impeded which matches the belief that the majority of mass in a galaxy is collisionless dark matter that felt no colliding interaction and passed right on through bringing the bulk of the gravitational lensing with it.

    Evidence 9: When galaxies merge, we can literally watch the collisionless dark matter passing through the other side via gravitational lensing.

  10. In 2009, Penny et al. showed that dark matter is required for fast rotating galaxies to not be ripped apart by tidal forces. And of course, the required amount is the exact same as what solves every other problem above.

    Evidence 10: Galaxies experience tidal forces that basic physics says should rip them apart and yet they remain stable. And the amount of unseen matter necessary to keep them stable is exactly what is needed for everything else.

  11. There are counter-theories, but as Sean Carroll does nicely here is to show how badly the counter theories work. They don't fit all the data. They are way more messy and complicated. They continue to be falsified by new experiments. Etc...

    To the contrary, Zwicky's proposed dark matter model from back in the 1930s continues to both explain and predict everything we observe flawlessly across multiple generations of scientists testing it independently. Hence dark matter is widely believed.

    Evidence 11: Dark matter theories have been around for more than 80 years, and not one alternative has ever been able to explain even most of the above. Except the original theory that has predicted it all.

Conclusion: Look, I know people love to express skepticism for dark matter for a whole host of reasons but at the end of the day, the vanilla theories of dark matter have passed literally dozens of tests without fail over many many decades now. Very independent tests across different research groups and generations. So personally I think that we have officially entered a realm where it's important for everyone to be skeptical of the claim that dark matter isn't real. Or the claim that scientists don't know what they are doing.

Also be skeptical when the inevitable media article comes out month after month saying someone has "debunked" dark matter because their theory explains some rotation curve from the 1930s. Skeptical because rotation curves are one of at least a dozen independent tests, not to mention 80 years of solid predictivity.

So there you go. These are some basic reasons to take dark matter seriously.

The crash of the Falcon Heavy center core by Fizrock in space

[–]DonHac 12.1k points12.1k points  (0 children)

Well, 18" and 300mph. When the cores are coming down they aim for a location next to the barge and only divert to on the barge at the last minute if everything is ok. This was going too fast, so no diversion.

‘I Went From Bad Student To NASA Astronaut’: Scott Kelly Owes His Glorious Career To Tom Wolfe's Book "The Right Stuff" by limka007 in space

[–]RKRagan 1682 points1683 points  (0 children)

I’ll answer and I’m going for electrical engineering. I’m 30 and got out of the navy at 27, started my AA degree at 28. I’m hoping to start my EE degree this summer. I don’t have much faith in my self due to my shitty study habits but it’s my best bet. I’m hoping to work for Tesla or SpaceX. I know people complain about how shitty it is to work there but I worked for the US Navy for 6 years. It cannot be worse. Plus it is something I’m actually passionate about.

A sun-like star 150 light-years away has 6 gas giants orbiting it, with 2 in the habitable zone by hominoid_in_NGC4594 in space

[–]LivingLosDream 534 points535 points  (0 children)

This is almost kind of “ho-hum here we go again” which is awesome since we find sooooo many planets out there now.

I teach astronomy, and it’s awesome to think that in 20 years, we will just know of hundreds of thousands, or even MILLIONS AND MILLIONS, of planets out there.

What a time to be alive.

In regards to that last part “what a time to be alive,” I also realize the Greeks probably thought they were brilliant, and now we look back at a lot of their knowledge and realize how dumb some of them were.

We will be looked at the same, which is great, because it shows we are constantly learning, and that is what life is all about. 👍

Edit. Thanks for the gold! It’s my first ever.

Interesting that I get my first ever gold in this subreddit considering gold was formed in the core of a star that went supernova. Awesome stuff! I love space!

I animated my picture of the Andromeda Galaxy by Idontlikecock in space

[–]Idontlikecock[S] 6841 points6842 points  (0 children)

Holy shit you're right. I can't believe I overlooked something so obvious...

Edit: fixed it and made some stars stationary https://gfycat.com/TiredGiddyEasternglasslizard

To celebrate its 5,000th day on Mars, NASA last week commanded the Opportunity rover to take a self portrait with its microscope camera- something it was never designed to do. by Pluto_and_Charon in space

[–]djellison 650 points651 points  (0 children)

So - I was on shift for this on Sol 5000 as the MI/ECAM PUL. Infact - it's something I've been thinking about for almost 10 years long before I even started working at JPL. I'll try and answer a few of the FAQs I'm seeing in here.....


We took the Microscopic Imager on the end of the robotic arm, turned it around and pointed it at the rover - took 17 images - and sent them back to Earth. Since then - the image processing team have had a go at assembling a mosaic. Because all the raw images go online, the awesome amateur community has assembled their own ( in this case, James Sorenson stitched the frames, Don Davis then colorized them) . To reduce the impact on science data coming down - we very heavily shrunk the images ( from 1024x1024 to 256x256 ) and used modest compression. The raw JPGs you see online have been compressed again so they look a bit worse. The calibrated data will be online in around 6 months time


Because it was Sol 5000! That only happens once. Infact, it shouldn't have EVER happened - despite many armchair experts saying we knew they'd last longer the expected lifetime really wasn't beyond the 90-100 sol range. We're coming out of winter, our solar panels are fairly clean so we're generating quite a lot of power. To use it we keep the rover awake from when it gets it's uplink (around 11.30am rover time) until the one mars relay pass it usually gets per day ( around 6pm each day ). So there was plenty of time and power to do something a bit unusual.......so we took damn selfie because we can, and she's 5000 sols old, and we've never seen her like this before.

Why are there bits missing

This is a mosaic of lots of tiny images. We took 17 on Sol 5000 and a few more on Sol 5006 which are on the Mars Images app - and Sol 5006 JSON feed, just not the website yet. The MI (Microscopic Imager ) only has about a 25 degree field of view - and the planning tools are obviously not designed for something like this. We did out best to get as much coverage of the rover as possible, We really couldn't get the right side of the rover (we got one extra frame over there on 5006) because of the risk of the end of the arm hitting its forearm, and the hard stops of the joint angles. It really wasn't designed for this....we did out best, and we're looking at cunning poses that we could put the arm in in the future that might let us do better. There will be a release to the Photojournal soon with a simulation of how we took it.

Here is an awesome stitch by James Sorenson of all the frames we took across Sol 5000 and 5006.

Why the Potato-Cam look?

A couple of reasons. Firstly - it's a camera built around 16 years ago, launched almost 15 years ago, and has been operating on Mars for more than 14 years - 56x longer than designed. On a good day, it's a 1024 x 1024 BnW fixed focus camera with a depth of field of around 3mm at its normal operational distance of 60mm or so from rock and soil targets. So it's very very out of focus. Because of that - and because we didn't want to consume much of the days data volume ( around 40 megabits was all we got down on Sol 5000....a fairly typical day. An uncompressed full frame microscopic imager image would be around 8 megabits ) we compressed the images in two ways. Firstly - we shrunk them from 1024 x 1024 to 256 x 256. That buys you an immediate 16x data reduction. We also used a reasonable level of compression onboard. Because it was just for fun, and we didn't want to encroach on the science also being done that day - we just made sure we didn't use a lot of data. Now we've learned how well it actually came out - we might try again at some point in the future with a little less compression. No promises :)

In YOUR face, Mark Watney.

I put a few details over at UMSF as well

I photographed myself looking at the Milky Way just before sunrise over the Atlantic Ocean. by marcuscotephoto in space

[–]Sosolidclaws 650 points651 points  (0 children)

I wish people could see that perspective every single day. The world would be a much better place. We're too detached from nature and space. It would go a long way to show how immense the universe is, how miniscule we are as a species, and how senseless it is to exploit each other when we should be united in love on this fragile blue marble suspended in the dark void of reality.

Welcome to Mars - Real picture from Mars Rover by CedrikG in space

[–]Pluto_and_Charon 6106 points6107 points  (0 children)

Wannabe geologist here, I'll explain what you're seeing:

  • Picture One shows layers of sandstone stacked up ontop of each other, formed when great sand dunes buried a dried up lake billions of years ago

  • Picture Two shows the slopes of Mount Sharp. At the top are recent sandstones and nobbles that were eroded by the wind over millions of years. At the base of the mountain of the image are black sand ripples (the sand on Mars is dark in colour), and clay-rich rocks formed at the bottom of the lake. You're looking at a vertical cross section through geologic time.

  • Picture Three shows mudstones formed at the bottom of an ancient lake. This terrain was very jaggedy and has cut holes in Curiosity's wheels.

  • Picture Four shows an ancient delta, the fan-shaped formation where a river poured into a lake. You can see a belt of black sand dunes in the background.

  • Picture Five is crisscrossed with white minerals. These features formed when groundwater circulated through rock and deposited white minerals in the cracks. Later the rock was eroded away by wind and sand action; these minerals are more resistant to erosion and so stick up out the ground.

  • Picture Six is one of the most important photos ever taken in Mars exploration. This image was taken right next to Curiosity's landing site back in 2012. It shows smooth, rounded pebbles of different composition to their surrounding rock, telling us they were transported great distances by liquid water (interestingly one of them is volcanic (igneous) in origin). We now know this was the first time a rover has visited what was once a fast-flowing stream on Mars.


All these pictures were taken by NASA's Curiosity rover which landed in Gale Crater in 2012. So far Curiosity has discovered that her crater was once an ancient lake that was habitable for hundreds of millions of years.

edit: Corrected a few descriptions. I'm using reverse image search to try and pinpoint what rock unit Curiosity is looking at.

edit2: I'll just leave /u/v7x 's brilliant map of ancient Mars here, which shows how we believe Mars used to look like 4 billion years ago. You can see Gale Lake, the lake that Curiosity's exploring, to the far right of the map- along the shoreline of the northern ocean, underneath the 'E' of 'Elysium'.