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4 minutes ago, MaartenVC said:

How the Earth moves through the universe. / Position is relative.
"Look around you. Where are you? Where is this place you are occupying? Somewhere in a room, maybe in a city on a continent on a planet orbiting a star in a galaxy among billions. But… where is all of that? While this may feel like a daft question, it turns out that the concept of an absolute position is something humans made up.
In a nutshell, the universe is a big bag of space that has things in it. If someone removed all these things, the stars and planets and black holes and dust, there would just be empty space left. In empty space, the concept of having a position loses all meaning. Empty space is uniform, the same everywhere."



This always trips me out concerning teleportation. You wouldn't just have to calculate your position on earth, but also where the solar system has travelled, how much space has expanded. Love it

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1 hour ago, MaartenVC said:

Empty space is uniform, the same everywhere.

One very hard illusion to break!

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Billions of years ago, a series of volcanic eruptions broke loose on the moon, blanketing hundreds of thousands of square miles of the orb’s surface in hot lava. Over the eons, that lava created the dark blotches, or maria, that give the face of the moon its familiar appearance today.

New research from CU Boulder suggests that volcanoes may have left another lasting impact on the lunar surface: sheets of ice that dot the moon’s poles and, in some places, could measure dozens or even hundreds of feet thick.



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Seems like Boeing finally successfully launched its reusable (uncrewed) crew-transporter and successfully docked it to the ISS.


Starliner Launches to Space Station on Uncrewed Flight Test for NASA



Station Crew Opens Boeing Starliner Hatch, Enters Spacecraft

The blue thing in the last picture is a dummy astronaut, strapped to the commander's seat, wearing Boeing's blue custom flight suit.

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  • 2 weeks later...


This image shows four sky maps made with the new ESA Gaia data released on 13 June 2022.
Click on the titles below to download the individual maps.

1. Radial velocity 

ESA’s Gaia data release 3 shows us the speed at which more than 30 million objects in the Milky Way (mostly stars) move towards or away from us. This is called ‘radial velocity’. We can now see how the objects move over a large portion of the Milky Way’s disc. 

The rotation of the disc, projected along the line-of-sight, is visible from the alternation of bright areas (moving away from us) and dark areas (moving toward us). Several objects whose radial velocity differs from that of their close environment are visible by contrast. 

The Large and Small Magellanic Clouds (LMC and SMC) appear as bright spots in the lower right corner of the image. The Sagittarius dwarf galaxy is visible as a faint quasi-vertical stripe below the Galactic Centre. Several globular clusters appear as tiny dots in the image, such as 47 Tucanae, the dark dot on the immediate left of the SMC.

2. Radial velocity and proper motion

This sky map shows the velocity field of the Milky Way for ~26 million stars. The colours show the radial velocities of stars along the line-of-sight. Blue shows the parts of the sky where the average motion of stars is towards us and red shows the regions where the average motion is away from us. The lines visible in the figure trace out the motion of stars projected on the sky (proper motion). These lines show how the direction of the speed of stars varies by galactic latitude and longitude. The Large and Small Magellanic Clouds (LMC and SMC) are not visible as only stars with well defined distances were selected to make this image. 

3. Interstellar dust

Gaia not only maps the stars in our galaxy but tells us what is in between the stars. The space between stars is not empty but instead filled with dust and gas clouds, out of which stars are born. 

Through the precise measurements of the stars' positions and their dispersed light, Gaia allows us to map the absorption of the starlight by the interstellar medium. Those maps provide us with essential clues to the physical mechanisms of the formation of stars, galaxies, and the history of our home galaxy.

This map shows the interstellar dust that fills the Milky Way. The dark regions in the centre of the Galactic plane in black are the regions with a lot of interstellar dust fading to the yellow as the amount of dust decreases.The dark blue regions above and below the Galactic plane are regions where there is little dust.

4. Chemical map

What stars are made of can tell us about their birthplace and their journey afterwards, and therefore about the history of the Milky Way. With today’s data release, Gaia is bringing us a chemical map of the galaxy. 

With Gaia, we see that some stars in our galaxy are made of primordial material, while others like our Sun are made of matter enriched by previous generations of stars. Stars that are closer to the centre and plane of our galaxy are richer in metals than stars at larger distances. 

This all-sky view shows a sample of the Milky Way stars in Gaia’s data release 3. The colour indicates the stellar metallicity. Redder stars are richer in metals.

© ESA/Gaia/DPAC; CC BY-SA 3.0 IGO, CC BY-SA 3.0 IGO 

Edited by MaartenVC
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  • 3 weeks later...

Go James Webb! 13B years ago. Lots of lensing. I didn't expect the infrared to produce color photos. Guess we'll get some cool images of this kind but for exoplanets... we're gonna need a bigger boat. 

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9 hours ago, trying to be less rude said:



Some more info on the NIRCam image of galaxy cluster SMACS 0723-73:

NASA’s James Webb Space Telescope has produced the deepest and sharpest infrared image of the distant universe to date. Known as Webb’s First Deep Field, this image of galaxy cluster SMACS 0723 is overflowing with detail.

Thousands of galaxies – including the faintest objects ever observed in the infrared – have appeared in Webb’s view for the first time. This slice of the vast universe covers a patch of sky approximately the size of a grain of sand held at arm’s length by someone on the ground.

This deep field, taken by Webb’s Near-Infrared Camera (NIRCam), is a composite made from images at different wavelengths, totaling 12.5 hours – achieving depths at infrared wavelengths beyond the Hubble Space Telescope’s deepest fields, which took weeks.

The image shows the galaxy cluster SMACS 0723 as it appeared 4.6 billion years ago. The combined mass of this galaxy cluster acts as a gravitational lens, magnifying much more distant galaxies behind it. Webb’s NIRCam has brought those distant galaxies into sharp focus – they have tiny, faint structures that have never been seen before, including star clusters and diffuse features. Researchers will soon begin to learn more about the galaxies’ masses, ages, histories, and compositions, as Webb seeks the earliest galaxies in the universe.

This image is among the telescope’s first-full color images. The full suite will be released Tuesday, July 12, beginning at 10:30 a.m. EDT, during a live NASA TV broadcast. Learn more about how to watch.

Image credit: NASA, ESA, CSA, and STScI

Higher resolution image here

More images will be posted here

Edited by MaartenVC
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2 hours ago, chim said:

I didn't expect the infrared to produce color photos.

I think that's done in post processing. The telescope sees in infrared, which is not what we see with our eyes. I think they 'translated' the infrared imagery into what you'd see in the visible spectrum. Perhaps they derived the different colors you see from the various infrared wavelengths that were used, but I really don't know how this stuff works. Just guessing, really.

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