Gravitational Lensing

Gravitational Lensing

Fomalhaut debris system ALMA Keck JWST
A surprising JWST discovery around Fomalhaut has a different, superior explanation: not a great dust cloud, but a mere background object.
life beyond earth
Back in 1990, we hadn't discovered a single planet outside of our Solar System. Here are 10 facts that would've surprised every astronomer.
lensing magnification curves dark matter wave
The best evidence for dark matter is astrophysical and indirect. Do new lensing observations point to ultra-light, wave-like dark matter?
JWST most distant galaxy proto-cluster
Finding out how the Universe grew up was the biggest science goal of JWST. This ultra-early proto-galaxy cluster is one amazing discovery.
photon paths around black hole
What do we mean by a black hole's size? A photon sphere? The minimal stable orbit? The event horizon? The singularity? Which one is right?
UNCOVER NIRCam mosaic
An incredible composite image of Pandora's Cluster, Abell 2744, simultaneously showcases both our impressive knowledge and vast ignorance.
Bullet Cluster separation mass gravity x-ray lensing
19 years ago, the Bullet Cluster provided an empirical proof for dark matter. Even today, modified gravity still can't explain it.
JWST Pandora's Cluster Abell 2744
Along with gravitational lensing and ALMA's incredible long-wavelength spectroscopy, JWST is reshaping our view of the early Universe.
Most globular clusters appear to form their stars all at once, but there are exceptions. JWST just observed how "second formations" happen.
globular cluster terzan 5
2022 was a year full of scientific discoveries and the dawn of the JWST. But Hubble's still going after 32 years. Here's the amazing proof!
JADES JWST z 13
Leaving Hubble in the dust, JWST has officially seen a galaxy from just 320 million years after the Big Bang: at just 2.3% its current age.
black hole
The strongest tests of curved space are only possible around the lowest-mass black holes of all. Their small event horizons are the key.
how much dark matter
The Universe gravitates so that normal matter and General Relativity alone can't explain it. Here's why dark matter beats modified gravity.
zodiac ptolemy harmonia macrocosmica
No planet enters retrograde more frequently than Mercury, which does so 3-4 times each year. Here’s the scientific explanation for why.
Einstein's relativity teaches us that time isn't absolute, but passes relatively for everyone. So how do telescopes see back through time?
The key problem with the dark matter hypothesis is that nobody knows what form dark matter might take.
sun gravity
With a telescope at just the right distance from the Sun, we could use its gravity to enhance and magnify a potentially inhabited planet.
JWST background galaxies Stephan's Quintet
We knew we'd find galaxies unlike any seen before in its first deep-field image. But the other images hold secrets even more profound.
jwst deep field
Even with only 12.5 hours of exposure time, James Webb's first deep-field image taught us lessons we've never realized before.
cosmic cliffs
Now that it's fully commissioned, the James Webb Space Telescope begins its exploration of the Universe. Here are its first science images!
With its very first deep-field view of the Universe now released, the James Webb Space Telescope has shown us our cosmos as never before.
james webb hubble
The James Webb Space Telescope has chosen 5 targets for its first science release. Here's what we know on the eve of JWST's big reveal!
With two different black hole event horizons now directly imaged, we can see that they are, in fact, rings, not disks. But why?
earendel
The Hubble Space Telescope, 32 years after its launch, broke the all-time record for most distant star. It won't do better.
earendel
The light from Earendel took 12.9 billion years to reach Hubble. The star is millions of times brighter than our Sun and 50 times as massive.
travel straight line
Is the Universe finite or infinite? Does it go on forever or loop back on itself? Here's what would happen if you traveled forever.
James Webb Hubble
Hubble's deepest views of space revealed fewer than 10% of the Universe's galaxies. James Webb will change that forever.
A color-enhanced image of Jupiter using data from the JunoCam camera..
With a new telescope on the horizon, we reflect on the best pictures of space that came before.
galaxies without dark matter
A few years ago, the first dark matter-free galaxies were announced, and then immediately disputed. Now, there are too many to ignore.