Since launching on Dec. 25, 2021, NASA's James Webb Space
Telescope (JWST) has been pelted by at least 19 tiny space rocks — including
one large one that left noticeable damage on one of the telescope's 18
In a sprawling new status report posted to the pre-print
database arXiv.org (opens in new tab), NASA researchers have shared the first
images showing the extent of that damage. Seen on the C3 mirror in the lower
right-hand corner of the image, the impact site appears as a single bright
white dent besmirching the golden mirror's surface.
The impact — which likely occurred between May 23 and May 25 this year — left "uncorrectable" damage to a tiny portion of that mirror, the report says. However, this little dent doesn't seem to have inhibited the telescope's performance at all. In fact, the JWST's performance is exceeding expectations "almost all across the board." (Good news for fans of stunning space images.)
Tiny rocks known as micrometeoroids are an all-too-familiar
threat to spacecraft in near-Earth orbit. The U.S. Space Surveillance Network
keeps track of more than 23,000 pieces of orbital debris measuring larger than
the size of a softball — however, the millions of nearby space chunks that are
smaller than that are almost impossible to monitor.
Instead, NASA and other space agencies plan for unavoidable
"Inevitably, any spacecraft will encounter micrometeoroids,"
the new report says. So far, six micrometeoroids have left noticeable
"deformities" on the JWST's mirrors, amounting to about one
noticeable impact per month since the telescope launched.
That's all within the realm of the expected. When building
the JWST, engineers intentionally hit mirror samples with micrometeoroid-sized
objects to test how such impacts would affect the telescope's performance.
What was unexpected, however, was the size of the larger
impactor that dented the C3 mirror. This space rock was seemingly larger than
the team had prepared for, and researchers are now trying to assess the impact
that further strikes like this could have on the JWST.
The new status report, which has not yet been peer-reviewed,
was authored by more than 200 scientists working at NASA, the European Space
Agency (a collaborator in the JWST's construction and launch, along with NASA
and the Canadian Space Agency) and other science institutions around the world.
Despite the unexpected impact to the C3 mirror, the researchers found that the
telescope is working flawlessly after the 6-month commissioning process, and
has a bright future of discovery ahead of it.
"JWST was envisioned 'to enable fundamental
breakthroughs in our understanding of the formation and evolution of galaxies,
stars, and planetary systems,'" the report says. "We now know with
certainty that it will."
NASA and SpaceX have agreed to study the feasibility of
awarding Elon Musk's company a contract to boost the Hubble Space Telescope to
a higher orbit, with a goal of extending its lifespan, the US space agency said
The renowned observatory has been operating since 1990 about
335 miles (540 kilometers) above Earth, in an orbit that slowly decays over
Hubble has no on-board propulsion to counter the small but
still present atmospheric drag in this region of space, and its altitude has
previously been restored during Space Shuttle missions.
The proposed new effort would involve a SpaceX Dragon
"A few months ago, SpaceX approached NASA with the idea
for a study whether a commercial crew could help reboost our Hubble
spacecraft," NASA's chief scientist Thomas Zurbuchen told reporters,
adding the agency had agreed to the study at no cost to itself.
He stressed there are no concrete plans at present to
conduct or fund such a mission until the technical challenges are better
One of the main obstacles would be that the Dragon
spacecraft, unlike the Space Shuttles, does not have a robotic arm and would
need modifications for such a mission.
SpaceX proposed the idea in partnership with the Polaris
Program, a private human spaceflight venture led by payments billionaire Jared
Isaacman, who last year chartered a SpaceX Crew Dragon to orbit the Earth with
three other private astronauts.
"This would certainly fit within the parameters we
established for the Polaris program," Isaacman said in response to a
question about whether reboosting Hubble could be the goal for a future Polaris
Asked by a reporter whether there might be a perception that
the mission was contrived in order to give wealthy people tasks to do in space,
Zurbuchen said: "I think it's only appropriate for us to look at this
because of the tremendous value this research asset has for us."
Arguably among the most valuable instruments in scientific
history, Hubble continues to make important discoveries, including this year
detecting the farthest individual star ever seen -- Earendel, whose light took
12.9 billion years to reach us.
It is currently forecast to remain operational throughout
this decade, with a 50 percent chance of de-orbiting in 2037, said Patrick
Crouse, Hubble Space Telescope project manager.
spacecraft successfully slammed into a distant asteroid at hypersonic speed on
Monday in the world's first test of a planetary defense system, designed to
prevent a potential doomsday meteorite collision with Earth.
Humanity's first attempt to alter the motion of an asteroid
or any celestial body played out in a NASA webcast from the mission operations
center outside Washington, DC, 10 months after DART was launched.
The livestream showed images taken by DART's camera as the
cube-shaped "impactor" vehicle, no bigger than a vending machine with
two rectangular solar arrays, streaked into the asteroid Dimorphos, about the
size of a football stadium, at 7:14 pm EDT (2314 GMT) some 6.8 million
miles (11 million km) from Earth.
The $330 million mission, some seven years in development,
was devised to determine if a spacecraft is capable of changing the trajectory
of an asteroid through sheer kinetic force, nudging it off course just enough
to keep Earth out of harm's way.
Whether the experiment succeeded beyond accomplishing its
intended impact will not be known until further ground-based telescope
observations of the asteroid next month. But NASA officials hailed the
immediate outcome of Monday's test, saying the spacecraft achieved its purpose.
"NASA works for the benefit of humanity, so for us it's
the ultimate fulfillment of our mission to do something like this - a
technology demonstration that, who knows, someday could save our home,"
NASA Deputy Administrator Pam Melroy, a retired astronaut, said minutes after
DART, launched by a SpaceX rocket in November 2021, made
most of its voyage under the guidance of NASA's flight directors, with control
handed over to an autonomous on-board navigation system in the final hours of
Monday evening's bullseye impact was monitored in near real
time from the mission operations center at the Johns Hopkins University Applied
Physics Laboratory in Laurel, Maryland.
Cheers erupted from the control room as second-by-second
images of the target asteroid, captured by DART's onboard camera, grew larger
and ultimately filled the TV screen of NASA's live webcast just before the
signal was lost, confirming the spacecraft had crashed into Dimorphos.
DART's celestial target was an oblong asteroid
"moonlet" about 560 feet (170 meters) in diameter that orbits a
parent asteroid five times larger called Didymos as part of a binary pair with
the same name, the Greek word for twin.
Neither object presents any actual threat to Earth, and NASA
scientists said their DART test could not create a new hazard by mistake.
Dimorphos and Didymos are both tiny compared with the
cataclysmic Chicxulub asteroid that struck Earth some 66 million years ago,
wiping out about three-quarters of the world's plant and animal species
including the dinosaurs.
Smaller asteroids are far more common and present a greater
theoretical concern in the near term, making the Didymos pair suitable test
subjects for their size, according to NASA scientists and planetary defense
experts. A Dimorphos-sized asteroid, while not capable of posing a planet-wide
threat, could level a major city with a direct hit.
Also, the two asteroids' relative proximity to Earth and
dual configuration make them ideal for the first proof-of-concept mission of
DART, short for Double Asteroid Redirection Test.
Robotic suicide mission
The mission represented a rare instance in which a NASA
spacecraft had to crash to succeed. DART flew directly into Dimorphos at 15,000
miles per hour (24,000 kph), creating the force scientists hope will be enough
to shift its orbital track closer to the parent asteroid.
APL engineers said the spacecraft was presumably smashed to
bits and left a small impact crater in the boulder-strewn surface of the
The DART team said it expects to shorten the orbital path of
Dimorphos by 10 minutes but would consider at least 73 seconds a success,
proving the exercise as a viable technique to deflect an asteroid on a
collision course with Earth - if one were ever discovered.
A nudge to asteroid millions of miles away years in advance
could be sufficient to safely reroute it.
Earlier calculations of the starting location and orbital
period of Dimorphos were made during a six-day observation period in July and
will be compared with post-impact measurements made in October to determine
whether the asteroid budged and by how much.
Monday's test also was observed by a camera mounted on a
briefcase-sized mini-spacecraft released from DART days in advance, as well as
by ground-based observatories and the Hubble and Webb space telescopes, but
images from those were not immediately available.
DART is the latest of several NASA missions in recent years
to explore and interact with asteroids, primordial rocky remnants from the
solar system's formation more than 4.5 billion years ago.
Last year, NASA launched a probe on a voyage to the Trojan
asteroid clusters orbiting near Jupiter, while the grab-and-go spacecraft
OSIRIS-REx is on its way back to Earth with a sample collected in October 2020
from the asteroid Bennu.
The Dimorphos moonlet is one of the smallest astronomical
objects to receive a permanent name and is one of 27,500 known near-Earth
asteroids of all sizes tracked by NASA. Although none are known to pose a
foreseeable hazard to humankind, NASA estimates that many more asteroids remain
undetected in the near-Earth vicinity.
A Chinese rocket fell
back to Earth on Saturday over the Indian Ocean but Nasa said Beijing had not
shared the "specific trajectory information" needed to know where
possible debris might fall.
US Space Command said the Long March 5B rocket
re-entered over the Indian Ocean at approximately 12:45 p.m. EDT Saturday (1645
GMT), but referred questions about "reentry's technical aspects such as
potential debris dispersal impact location" to China.
"All spacefaring nations should follow established best
practices and do their part to share this type of information in advance to
allow reliable predictions of potential debris impact risk," Nasa
Administrator Bill Nelson said. "Doing so is critical to the responsible
use of space and to ensure the safety of people here on Earth."
Social media users in Malaysia posted video of what appeared
to be rocket debris.
Aerospace Corp, a government funded nonprofit research
center near Los Angeles, said it was reckless to allow the rocket's entire
main-core stage – which weighs 22.5 tons (about 48,500 lb) – to return to Earth
in an uncontrolled reentry.
Earlier this week, analysts said the rocket body would
disintegrate as it plunged through the atmosphere but is large enough that
numerous chunks will likely survive a fiery re-entry to rain debris over an
area some 2,000 km (1,240 miles) long by about 70 km (44 miles) wide.
The Chinese Embassy in Washington did not immediately
comment. China said earlier this week it would closely track the debris but
said it posed little risk to anyone on the ground.
The Long March 5B blasted off July 24 to deliver a
laboratory module to the new Chinese space station under construction in orbit,
marking the third flight of China's most powerful rocket since its maiden
launch in 2020.
Fragments of another Chinese Long March 5B landed on the
Ivory Coast in 2020, damaging several buildings in that West African nation,
though no injuries were reported.
By contrast, he said, the United States and most other
space-faring nations generally go to the added expense of designing their
rockets to avoid large, uncontrolled re-entries - an imperative largely
observed since large chunks of the Nasa space station Skylab fell from orbit in
1979 and landed in Australia.
Last year, Nasa and others accused China of being opaque
after the Beijing government kept silent about the estimated debris trajectory
or the reentry window of its last Long March rocket flight in May 2021.
Debris from that flight ended up landing harmlessly in the
The powerful James
Webb Space Telescope's inaugural batch of images has opened a new chapter of
cosmic exploration, but astronomers say the observatory's most consequential
discoveries may well be those they have yet to even imagine.
Distant colliding galaxies, gas-giant exoplanets and dying
star systems were the first celestial subjects captured by the
multibillion-dollar observatory, putting its wide range of infrared-imaging
capabilities on colorful display and proving the telescope works as designed.
Webb's gallery of early photos and spectrographic data,
which astronomers likened to the results of mere "target practice" as
they readied the telescope for operational science, also previewed several
planned areas of inquiry ahead.
The competitively-selected agenda of research includes
exploring the evolution of early galaxies, the life cycle of stars, the search
for habitable planets orbiting distant suns, and the composition of moons in
our own outer solar system.
But the most revolutionary findings by Webb, 100 times more
sensitive than its 30-year-old predecessor, the still-operational Hubble Space
Telescope, may turn out to be accidental discoveries or answers to questions
astronomers have yet to ask.
"Who knows what's coming for JWST. But I'm sure we're
going to have a lot of surprises," René Doyon, principal investigator for
one of Webb's instruments, the Near-Infrared Imager and Slitless Spectrograph,
said Tuesday at NASA's Goddard Space Flight Center in Maryland, where the
agency unveiled the observatory's first full-color images.
With Webb open for business seven months after its launch in
December, astronomers are preparing for "something that's out there that
we never guessed would be there at all," said John Mather, a Nobel
Prize-winning senior astrophysicist at NASA whose work during the 1990s helped
cement cosmology's 'Big Bang' theory.
DARK MATTER, DARK ENERGY
Mather and other scientists pointed to dark matter, an
invisible and little-understood but theoretically influential cosmic
scaffolding, as an enigma that Webb might unlock during its mission.
Hubble, likewise, opened a whole new field of astrophysics
devoted to another mysterious phenomenon, dark energy, as its observations of
supernovas led to the unexpected discovery that the universe's expansion is
Taken together, dark energy and dark matter are now
estimated by scientists to account for 95% of the known universe. All the
galaxies, planets, dust, gases and other visible matter in the cosmos compose
"Those were huge surprises," Mather said of early
dark matter and dark energy discoveries.
Amber Straughn, a deputy project scientist working with
Webb, said: "It's hard to imagine what we might learn with this
hundred-times-more-powerful instrument that we really don't know yet."
Dark matter already has figured prominently in Webb's very
first "deep field" image, a composite photo of a distant galaxy
cluster, SMACS 0723, that offers the most detailed glimpse to date of the early
universe thanks to a magnifying effect called a gravitational lens.
The sheer combined mass of galaxies and other unseen matter
in the foreground of the image warps the surrounding space enough to amplify
light coming from more distant galaxies behind them, bringing into view fainter
objects farther away, and thus further back in time.
At least one of the tiny specks of light
"photo-bombing" the edge of the picture dates back 13.1 billion
years, or nearly 95% of the way to the Big Bang, the theoretical cosmic
flashpoint that put the universe in motion 13.8 billion years ago.
But because the calculated combined mass of all the visible
matter in the foreground is insufficient by itself to produce the faint
circular distortion seen in the image, the lensing effect is firm indirect
evidence of dark matter's presence.
"It's the most powerful tool that we have,
astrophysically, to do this type of lensing experiment," said Jane Rigby,
a Webb operations project scientist. "We can't directly detect dark
matter, but we see its impact... we can see its effects in action."
"The universe has been out there, we just had to build
a telescope to see what was there," she added.
New light was also shed unexpectedly from Webb's first
spectrographic analysis of an exoplanet in a distant solar system, in this case
a gas giant roughly the size of Jupiter dubbed WASP-96 b.
Measuring the wavelengths from light filtered through the
atmosphere of the exoplanet as it orbited its own sun clearly revealed the
molecular signature of water vapor in clouds and haze, features scientists were
surprised to find.
"There are discoveries in these data," Webb
program scientist Eric Smith said. "We're making discoveries and we really
haven't even started trying yet."
US President Joe
Biden, pausing from political pressures to bask in the glow of the cosmos, on
Monday released the debut photo from NASA's James Webb Space Telescope - an
image of a galaxy cluster revealing the most detailed glimpse of the early
universe ever seen.
The White House sneak peek of Webb's first high-resolution,
full-color image came on the eve of a larger unveiling of photos and
spectrographic data that NASA plans to showcase on Tuesday at the Goddard Space
Flight Center in suburban Maryland.
The $9 billion Webb observatory, the largest and most
powerful space science telescope ever launched, was designed to peer through
the cosmos to the dawn of the known universe, ushering in a revolutionary era
of astronomical discovery.
The image showcased by Biden and NASA chief Bill Nelson
showed the 4.6 billion-year-old galaxy cluster named SMACS 0723, whose combined
mass acts as a "gravitational lens," distorting space to greatly
magnify the light coming from more distant galaxies behind it.
At least one of the faint, older specs of light appearing in
the "background" of the photo - a composite of images of different
wavelengths of light - dates back more than 13 billion years, Nelson said. That
makes it just 800 million years younger than the Big Bang, the theoretical
flashpoint that set the expansion of the known universe in motion some 13.8
billion years ago.
"It's a new window into the history of our
universe," Biden said before the picture was unveiled. "And today
we're going to get a glimpse of the first light to shine through that window:
light from other worlds, orbiting stars far beyond our own. It's astounding to
He was joined at the Old Executive Office Building of the
White House complex by Vice President Kamala Harris, who chairs the US National
FROM GRAIN OF SAND IN THE SKY
On Friday, the space agency posted a list of five celestial
subjects chosen for its showcase debut of Webb. These include SMACS 0723, a
bejeweled-like sliver of the distant cosmos that according to NASA offers
"the most detailed view of the early universe to date." It also
constitutes the deepest and sharpest infrared image of the distant cosmos ever
The thousands of galaxies were captured in a tiny patch of
the sky roughly the size of a grain of sand held at arm's length by someone
standing on Earth, Nelson said.
Webb was constructed under contract by aerospace giant
Northrop Grumman Corp . It was launched to space for NASA and its European and
Canadian counterparts on Christmas Day 2021 from French Guiana, on the
northeastern coast of South America.
The highly anticipated release of its first imagery follows
six months of remotely unfurling Webb's various components, aligning its
mirrors and calibrating instruments.
With Webb now finely tuned and fully focused, scientists
will embark on a competitively selected list of missions exploring the evolution
of galaxies, the life cycles of stars, the atmospheres of distant exoplanets
and the moons of our outer solar system.
Built to view its subjects chiefly in the infrared spectrum,
Webb is about 100 times more sensitive than its 30-year-old predecessor, the
Hubble Space Telescope, which operates mainly at optical and ultraviolet
The much larger light-collecting surface of Webb's primary
mirror - an array of 18 hexagonal segments of gold-coated beryllium metal -
enables it to observe objects at greater distances, thus further back in time,
than Hubble or any other telescope.
All five of Webb's introductory targets were previously
known to scientists. Among them are two enormous clouds of gas and dust blasted
into space by stellar explosions to form incubators for new stars - the Carina
Nebula and the Southern Ring Nebula, each thousands of light years away from
The collection also includes a galaxy clusters known as
Stephan's Quintet, which was first discovered in 1877 and encompasses several
galaxies described by NASA as "locked in a cosmic dance of repeated close
NASA will also present Webb's first spectrographic analysis
of an exoplanet - one roughly half the mass of Jupiter that lies more than
1,100 light years away - revealing the molecular signatures of filtered light
passing through its atmosphere.