Travel the universe with Dr. Ethan Siegel as he answers the biggest questions of all
Just say no to artist’s illustrations. This is what the Universe actually looks like.
The Universe we observe often surpasses our greatest imaginings.
This 20-year time-lapse of stars near the center of our galaxy comes from the ESO, published in 2018. Note how the resolution and sensitivity of the features sharpen and improve towards the end, and how the central stars all orbit an invisible point: our galaxy’s central black hole. (ESO/MPE)
Here are 10 genuine photos that might surpass yours.
The protoplanetary disk around the star HL Tauri in a young star cluster may well be the best analogue of a Sun-like star forming, with planets around it, that we’ve ever seen. This was ALMA’s first protoplanetary disk to display the rings and gaps, and since that time ALMA, DSHARP, and other collaborations have measured many dozens of protoplanetary disks. (ALMA (ESO/NAOJ/NRAO)/NASA/ESA)
10.) Protoplanetary disks with gaps. Planetesimals accrete material from surrounding orbits, creating gaps where planets arise.
The most spectacular movie from ESA’s Rosetta mission shows what the surface of comet 67P/Churyumov-Gerasimenko looks like, including the volatile ices that sublimate and re-freeze when they’re in sunlight or shadow, respectively, causing this snow-like behavior. (ESA/ROSETTA/NAVCAM)
9.) Snowy weather on comets. The ESA’s Rosetta mission witnessed cometary “snow” firsthand.
Direct imaging of four planets orbiting the star HR 8799, 129 light-years away from Earth, a feat accomplished through the work of Jason Wang and Christian Marois. The second generation of stars may have already had rocky planets orbiting them. (J. WANG (UC BERKELEY) & C. MAROIS (HERZBERG ASTROPHYSICS), NEXSS (NASA), KECK OBS.)
8.) Exo-Jupiters are directly imaged. Observing nearby, face-on systems reveals sufficiently well-separated gas giants.
Within Saturn’s rings, many small moons and moonlets, such as Daphnis, can be found. These objects are likely created by accreting particles, then destroyed by collisions and tidal forces. their uniform composition and decaying nature suggests that they were created relatively recently, with one longstanding theory contending that a larger, destroyed moon gave them their origin as little as tens but as many as hundreds of millions of years ago. (NASA / JPL-CALTECH / SPACE SCIENCE INSTITUTE)
7.) Interior moons carve “waves” in Saturn’s rings. Temporary moons and moonlets form via accretion, perturbing nearby materials.
Triton’s south polar terrain photographed by the Voyager 2 spacecraft. About 50 dark plumes mark what are thought to be cryovolcanoes, with those trails being caused by the phenomenon colloquially called ‘black smokers.’ (NASA / VOYAGER 2)
6.) Volcanoes on Neptune’s largest moon, Triton. Some 50 dark plumes — cryovolcanoes — were seen on Triton by NASA’s Voyager 2.
The two-toned nature of Iapetus was a mystery for some 300+ years, but was finally solved by the Cassini mission in the 21st century, as dark material from Phoebe ‘splats’ into Iapetus, holding more heat and boiling off any volatile ices that land there. (NASA / JPL)
5.) Saturn’s moon Iapetus is two dramatically different colors. Phoebe, an outer, captured moon, offgasses, darkening Iapetus’s “forward”-moving hemisphere.
Jupiter’s moon Io, with (then-)active volcanoes Loki and Pele, is eclipsed by Europa as viewed from Earth in 2015. This animation showcases a preview of the power that will be available to astronomers when 30-meter class telescopes come online. (LBTO)
A horseshoe-shaped Einstein ring, just short of the perfect alignment needed for a 360-degree ring. Systems like this were used to place a strong constraint on the validity of relativity, enabling us to constrain alternatives to Einstein’s theory of gravity even further. (NASA/ESA AND HUBBLE)
3.) A ‘horseshoe’ in space. Massive objects bend spacetime, creating gravitational lenses, stretching background galaxies into near-perfect “Einstein rings.”
The Red Rectangle Nebula, so called because of its red color and unique rectangular shape, is a preplanetary nebula in the Monoceros constellation. It is part of a binary star system, where one member is ejecting the hydrogen gas in the post-AGB phase. This system will someday evolve, but has not yet evolved, into a full fledged planetary nebula. (ESA/HUBBLE & NASA)
2.) The Red Rectangle Nebula. Late-stage, massive stars eject hydrogen gas, where gravity, ionization, shocks, companions, and radiation sculpt these diffuse outflows.
Sunset photographed from Gale Crater by the Mars Curiosity rover on April 15, 2015. The four images shown in sequence here were taken over a span of 6 minutes, 51 seconds using the left eye of the rover’s Mastcam. (NASA / JPL-CALTECH)
1.) A blue Martian sunset. NASA’s Curiosity rover captured blue sunsets on the red planet. Its next-generation successor, Perseverance, arrives on February 18, 2021.
Mostly Mute Monday tells an astronomical story in images, visuals, and no more than 200 words. Talk less; smile more.
