4 Cosmic Records That The James Webb Space Telescope Should Shatter
“With seven times Hubble’s light-gathering power, better resolution, and extended infrared capabilities, numerous cosmic records will fall. Although it will almost certainly make unforeseen discoveries, Webb is poised to shatter four separate cosmic records.
1.) Most distant galaxy. Presently, the Hubble Space Telescope holds the record, discovering GN-z11 from just 407 million years after the Big Bang. Webb’s infrared eyes will see through the cosmic dust that obscures Hubble’s vision, revealing galaxies as little as 200-275 million years old.”
We’ve come so far in our exploration and understanding of the Universe, and yet the next generation of telescopes that are going to be completed and are set to begin operating in the 2020s will truly be a revolution. Next year, the James Webb Space Telescope will launch and begin data-taking for its first science missions, and numerous cosmic records should fall almost immediately. These include the most distant galaxy, measuring the components of the atmospheres of the smallest exoplanets, finding the earliest stellar populations ever, and taking direct images of the smallest exoplanets ever seen.
Come see what’s ahead just over the horizon for astronomy in images, visuals, and no more than 200 words in this latest story today!
Not Only Didn’t We Find Water On An Earth-Like Exoplanet, But We Can’t With Current Technology
“Over the past few decades, astronomers have uncovered thousands of new exoplanets. Some of them are rocky; some are temperate; some have water. However, the idea that exoplanet K2-18b is rocky, Earth-like, and has liquid water is absurd, despite recent headlines. Light filters through K2-18b’s atmosphere when it passes in front of its star, enabling us to measure what’s absorbed. Based on those absorption lines, the presence of many chemicals can be inferred, including water. K2-18b is, truly, the first known habitable-zone exoplanet to contain water. However, it is not rocky; its mass and radius are too large, necessitating a large gas envelope around it.”
How incredible was that report that came out last week: the first Earth-like, rocky exoplanet with liquid water on its surface has been discovered! If it were true, it would be incredible. Well, what we did find is still pretty remarkable, but it’s very different from what you’ve likely heard.
We did find water on the exoplanet in question, K2-18b, but only in the vapor phase and only in the atmosphere.
The exoplanet is closer to Earth in terms of mass and radius than any other with water on it, but the planet is still too massive and large to be rocky. It must have an envelope of hydrogen and helium, and both have had their presence detected.
If we want to find atmospheric biosignatures around Earth-like worlds, we need better observatories. Let’s build them! Here’s the real story.
Is This The Most Massive Star In The Universe?
“Within our own Milky Way, massive star-forming regions, like NGC 3603, house many stars over 100 times our Sun’s mass. As a member of a binary system, HD 15558 A is the most massive star with a definitive value: 152 solar masses. However, all stellar mass records originate from the star forming region 30 Doradus in the Large Magellanic Cloud. Known as the Tarantula Nebula, it has a mass of ~450,000 Suns and contains over 10,000 stars. The central star cluster, R136, contains 72 of the brightest, most massive classes of star.”
The most massive stars are the shortest-lived ones, with lifetimes of only 1-to-3 million years. If we hope to find them, we have to look in regions that are actively forming stars today. The largest, most massive star-forming region in our Local Group is the Tarantula Nebula, found in the Large Magellanic Cloud. Unsurprisingly, it’s the location of the nearest supernova to Earth we’ve seen in the past century, and contains dozens of the brightest, most massive class of star inside. The current record-holder, R136a1, has over 250 times the mass of the Sun.
Yet, once the James Webb Space Telescope comes online, we might absolutely demolish that record. How? And how come? Find out today.
We Have Now Reached The Limits Of The Hubble Space Telescope
“Finally, there are the wavelength limits as well. Stars emits a wide variety of light, from the ultraviolet through the optical and into the infrared. It’s no coincidence that this is what Hubble was designed for: to look for light that’s of the same variety and wavelengths that we know stars emit.
But this, too, is fundamentally limiting. You see, as light travels through the Universe, the fabric of space itself is expanding. This causes the light, even if it’s emitted with intrinsically short wavelengths, to have its wavelength stretched by the expansion of space. By the time it arrives at our eyes, it’s redshifted by a particular factor that’s determined by the expansion rate of the Universe and the object’s distance from us.
Hubble’s wavelength range sets a fundamental limit to how far back we can see: to when the Universe is around 400 million years old, but no earlier.”
The Hubble Space Telescope, currently entering its 30th year of service, has literally revolutionized our view of the Universe. It’s shown us our faintest and most distant stars, galaxies, and galaxy clusters of all. But as far back as it’s taken us, and as spectacular as what it’s revealed, there is much, much more Universe out there, and Hubble is at its limit.
Here’s how far we’ve come, with a look to how much farther we could yet go. It’s up to us to build the tools to take us there.
Ask Ethan: What Will Our First Direct Image Of An Earth-Like Exoplanet Look Like?
“[W]hat kind of resolution can we expect? [A] few pixels only or some features visible?”
I’ve got good news and bad news. With the next generation of space-based and ground-based telescopes on the way, we’ll finally be able to image Earth-sized and super-Earth-sized planets around the nearest stars to us directly. Unfortunately, even the largest of these telescopes won’t be able to resolve these planets beyond being a single pixel (with light leaking into the adjacent pixels) in angular size. But even with that limitation, we should be able to recover signatures of continents, oceans, icecaps, clouds, atmospheric contents, water, and potentially even life.
Come find out what we will (and won’t) be able to do with our first direct images of Earth-sized exoplanets, coming to you in just a few years!
This Is How We Will Discover The Most Distant Galaxy Ever
“Sometime in the distant past, likely when the Universe was less than 2% its current age, the very first galaxy of all formed when massive star clusters merged together, resulting in an unprecedented burst of star formation. The high-energy light from these stars struggles to escape, but the longer-wavelength light can penetrate farther through neutral atoms. The expansion of the Universe redshifts all the light, stretching it far beyond anything Hubble could potentially observe, but next-generation infrared telescopes should be able to catch it. And if we observe the right part of the sky, with the right instruments, for a sufficiently long time to reveal the right details about these objects, we’ll push back the cosmic frontier of the first galaxies even farther.
Somewhere, the most distant, first galaxy of all is out there, waiting to be discovered. As the 2020s approach, we can feel confident that we’ll not only shatter the current cosmic record-holder, but we know exactly how we’ll do it.”
13.8 billion years ago, our Universe as-we-know-it began with the hot Big Bang. There were no stars or galaxies back then; there weren’t even bound structures of any type. Everything was too energetic, and would immediately be destroyed by the unfathomably high temperatures and energies that every particle possessed. Yet, with time, the Universe expanded and cooled. Protons, nuclei, and neutral atoms formed; overdense regions gravitationally pulled-in mass and matter; stars were born, lived, died, and new stars were born in their aftermath. At some point, the first large star clusters merged together, passing a critical threshold and forming the first galaxy in the Universe.
That’s what we want to find. We’ve gone back to when the Universe was just 3% its present age, but that’s not enough. We must go father. We must find the first one. Here’s how we’ll do it.
Happy Halloween from Starts With A Bang!
In a first, I have gone full-astrophysics for Halloween this year.
In all its golden glory, I have put together a James Webb Space Telescope costume this year, complete with sunshield and all!
Happy Halloween, Tumblr!
This Is How Hubble Will Use Its Remaining Gyroscopes To Maneuver In Space
“It might seem to be just another example of crumbling infrastructure in the United States, but you must neither underestimate Hubble nor the resourcefulness of astronomers and scientists and engineers overall. The two (or maybe three) remaining gyroscopes are of a new and upgraded design, designed to last five times as long as the original gyroscopes, which includes the one that recently failed. The James Webb Space Telescope, despite being billed as Hubble’s successor, is actually quite different, and will launch in 2021.
Even with one gyroscope, the Hubble Space Telescope should still be operational and capable of providing complementary observations to James Webb. This reduced-gyro mode has been planned for a long time. The only disappointment is that we may need to enter it so soon.”
One of the hallmarks of a successful NASA project is overengineering. Things will go wrong, break down, and degrade over time. One of the best examples is the Opportunity rover, which was designed for a 90 day mission and wound up living for nearly 15 years. But many people don’t appreciate how successfully overengineered Hubble is. Now well into its 28th year, it’s some 9 years removed from its final servicing mission. The gyroscopes that were installed included three of the old type and three of the new type, and the final old-style gyroscope has just failed.
Yet Hubble can continue operating and doing astronomy on just one gyroscope. Its demise has been greatly exaggerated; come learn the truth about Hubble today!
This Is Why Hubble Can’t See The Very First Galaxies
“By observing dark, empty patches of sky, it reveals ancient galaxies without nearby interference.
When distant galaxy clusters are present, these massive gravitational clumps behave as natural magnifying lenses.
The most distant observed galaxies have their light bent, distorted, and amplified along the journey.
Hubble discovered the current cosmic record-holder, GN-z11, via lensing.
Its light arrives from 407 million years after the Big Bang: 3% of the Universe’s current age.”
No astronomical observatory has revolutionized our view of the Universe quite like NASA’s Hubble Space Telescope. With the various servicing missions and instrument upgrades that have taken place over its lifetime, Hubble has pushed back the cosmic frontier of the first stars and galaxies to limits never before known. Yet there must be galaxies before them; some of the most distant Hubble galaxies have stars in them that push back the time of the first galaxies to just 250 million years after the Big Bang. Yet Hubble is physically incapable of seeing that far. Three factors: cosmic redshift, warm temperatures, and light-blocking gas, prevent us from going much beyond what we’ve already seen. In fact, we’re remarkably lucky to have gotten as distant as we have.
Find out why Hubble can’t see the very first galaxies, and why we need the James Webb space telescope!
First Stars Formed No Later Than 250 Million Years After The Big Bang, With Direct Proof
“We see MACS1149-JD1 as it was 530 million years after the Big Bang, while inside, it has a special signature: oxygen. Oxygen is only produced by previous generations of stars, indicating that this galaxy is already old.
MACS1149-JD1 was imaged with microwave (ALMA), infrared (Spitzer), and optical (Hubble) data combined.
The results indicate that stars existed nearly 300 million years before our observations.”
One of the great quests of astronomers today is to measure and locate the very first stars in the Universe. As far back as Hubble can see, to when the Universe was just 3-5% its current age, the Universe is still full of galaxies, even though they’re smaller and bluer than the ones we have today. But within these galaxies, we can also find evidence that the stars in there aren’t the very first ones; they contain evidence for prior generations of stars in their spectral signatures. From the second-most distant galaxy ever discovered, itself just 530 million years after the Big Bang, we see evolved stars. They indicate that the very first ones formed no later than 250 million years after the Big Bang.
The James Webb Space Telescope will be able to see that far! In less than 3 years, we’ll peer beyond where we’ve ever seen before. And there will no doubt be something breathtaking to look at.