On the night of Wednesday, July 13, take a look at the full moon, a “supermoon.” Since it is closest to Earth in its elliptical orbit, the moon will look 14% larger and 30% brighter than when it is farthest from Earth (but only 7% larger and 15% brighter than an average full moon) — nice to see, though not the big deal that the press often makes of supermoons (they typically occur a few times per year). The view will be nearly as good on Tuesday and Thursday nights, in case Wednesday isn’t convenient for you or clouds are forecast.
What IS a big deal, though, is the first full-color, ”real science” image from the James Webb Space Telescope (JWST), released on Monday and attached here. It’s truly stunning! Showing a patch of sky just the size of a grain of sand held at arm’s length, it reveals thousands of distant galaxies — gravitationally bound collections of billions of stars (like the Milky Way Galaxy). This is the ”deepest” image of the Universe ever obtained, meaning that it shows the faintest and among the most distant objects ever seen, and it took 12.5 hours of observing at different wavelengths (colors of light) primarily in the infrared (longer wavelengths than visible light — what we often refer to as heat radiation, like from glowing coals).
The image is centered on a massive cluster of galaxies known as SMACS 0723, about 4.6 billion light years away (meaning that the light we are now seeing left those galaxies roughly when Earth and our Solar System was being formed!). It has a giant galaxy in the middle that’s gradually gobbling up other, smaller galaxies in the cluster. Surrounding the cluster are more-distant galaxies, some perhaps more than 13 billion light years away. Many of them are magnified in brightness and distorted into arc shapes because of the ”warping” of space (and time) caused by the massive cluster and predicted by Einstein’s theory of gravity (the general theory of relativity) — an effect called ”gravitational lensing.” The beauty and grandeur of this image are mind-boggling — as is the amount of information in it. (By the way, don’t pay attention to the few objects with six spikes coming out of them — these are stars in our own Milky Way Galaxy, and the spikes are a ”diffraction pattern” produced by the 18 hexagonal segments of JWST’s main mirror. They don’t appear in the images of faint, distant, fuzzy galaxies.)
On Tuesday, July 12, NASA’s main press conference about the first results from JWST will take place, and I encourage you to watch it (or read about the findings online, since you may receive this message too late — apologies). Opening remarks will be at 6:45 am PDT, and four new images will be shown and discussed in succession starting at 7:30 am PDT. There will be a news conference at 9:30 am PDT with more details about the images. Here’s a brief summary.
(1) The Carina Nebula is a cloud of gas and dust 7500 light years away (a light year is 6 million million miles) that can be thought of as a stellar nursery (in which stars have recently been born and are still being born). Many of those stars are very massive and hot. Our own Solar System formed about 4.6 billion years ago from a cloud similar to (but almost certainly much smaller than) this one.
(2) WASP-96b is a planet orbiting another star with a period of only 3.4 days, about half the mass of Jupiter and 1150 light years away from Earth. Its infrared spectrum will be shown, possibly revealing whether the planet has an atmosphere. In future studies of this type, astronomers hope to detect possible biosignatures (such as oxygen and methane) in the atmospheres of exoplanets.
(3) The Southern Ring Nebula is a ”planetary nebula” — gas that was gently ejected by a dying central star and is now glowing by a process similar to fluorescence (the central star is hot, and the UV light that it emits ionizes the surrounding cloud of gas, which then glows). It is about 2000 light years from Earth. Our own Sun will produce a similar object in about 7 billion years — so this is a sneak preview of its future. (“Planetary nebula” is actually a misnomer … the object only looks vaguely like a planet.)
(4) Stephan’s Quintet is a famous group of five galaxies, four of which are at nearly the same distance from Earth (about 290 million light years) and gravitationally interacting with each other in a cosmic dance. (The fifth galaxy is unrelated, and just happens to be along the same line of sight.) There might be a side-by-side comparison of what the Hubble Space Telescope records at visible (optical) wavelengths and what JWST detects in the infrared.
These promise to be amazing images and results! I’m absolutely thrilled that JWST is working correctly. Honestly, a year ago I had serious doubts that the mission would be successful, given the 340+ potential single-point failures. Kudos to NASA and all the people involved in the planning, construction, launch, unfolding, and commissioning of JWST!
I’m looking forward to getting JWST data in the coming year, for two approved studies regarding exploding stars (supernovae) — we are trying to see how much dust they form in the ejected gases. Some of this dust much later becomes incorporated into giant clouds of gas and dust like the Carina Nebula, forming new stars and planetary systems. Exciting stuff, indeed!
With best wishes,
P.S. Let me also alert you to a press release that my team sent out on Monday, regarding observations of the nearest known example of a star that was shredded, or ”spaghettified,” after approaching too close to a supermassive black hole at the center of a galaxy:
This study was led by one of my graduate students, Kishore Patra. I’ll provide some more details (via email) later, after we compose and release another press release about a different study we’ve completed… but I want to keep this message focused on the JWST results.