For the second time in history, a human-made object has reached the space between the stars. Our Voyager 2 probe now has exited the heliosphere – the protective bubble of particles and magnetic fields created by the Sun.
Comparing data from different instruments aboard the trailblazing spacecraft, mission scientists determined the probe crossed the outer edge of the heliosphere on Nov. 5. This boundary, called the heliopause, is where the tenuous, hot solar wind meets the cold, dense interstellar medium. Its twin, Voyager 1, crossed this boundary in 2012, but Voyager 2 carries a working instrument that will provide first-of-its-kind observations of the nature of this gateway into interstellar space.
Voyager 2 now is slightly more than 11 billion miles (18 billion kilometers) from Earth. Mission operators still can communicate with Voyager 2 as it enters this new phase of its journey, but information – moving at the speed of light – takes about 16.5 hours to travel from the spacecraft to Earth. By comparison, light traveling from the Sun takes about eight minutes to reach Earth.
Our latest space telescope, Transiting Exoplanet Survey Satellite (TESS), launched in April. This
week, planet hunters worldwide received all the data from the first two months
of its planet search. This view, from four cameras on TESS, shows just one
region of Earth’s southern sky.
The Transiting Exoplanet Survey Satellite (TESS) captured
this strip of stars and galaxies in the southern sky during one 30-minute
period in August. Created by combining the view from all four of its cameras, TESS
images will be used to discover new exoplanets. Notable features in this swath
include the Large and Small Magellanic Clouds and a globular cluster called NGC
104. The brightest stars, Beta Gruis and R Doradus, saturated an entire column
of camera detector pixels on the satellite’s second and fourth cameras.
The data in the images from TESS will soon lead to discoveries of
planets beyond our solar system – exoplanets. (We’re at 3,848 so far!)
But first, all that data (about 27 gigabytes a day) needs to be
processed. And where do space telescopes like TESS get their data cleaned up?
At the Star Wash, of course!
TESS sends about 10 billion pixels of data to Earth
at a time. A supercomputer at NASA Ames in Silicon Valley processes the raw
data, turning those pixels into measures of a star’s brightness.
And that brightness? THAT’S HOW WE FIND PLANETS! A dip in a star’s
brightness can reveal an orbiting exoplanet in transit.
TESS will spend a year studying our southern sky, then will turn
and survey our northern sky for another year. Eventually, the space telescope
will observe 85 percent of Earth’s sky, including 200,000 of the brightest and
closest stars to Earth.
Did you know our Milky Way galaxy is blowing
bubbles? Two of them, each 25,000 light-years tall! They extend above and below
the disk of the galaxy, like the two halves of an hourglass. We can’t see them
with our own eyes because they’re only apparent in gamma-ray light, the highest-energy light in the
One possible explanation is that they could be
leftovers from the last big meal eaten by the supermassive black hole at the
center of our galaxy. This monster is more than 4 million times the mass of our
own Sun. Scientists think it may have slurped up a big cloud of hydrogen
and 9 million years ago and then burped jets of hot gas
that we see in gamma rays and X-rays.
Another possible explanation is that the bubbles
could be the remains of star formation. There are massive clusters of stars at
very the center of the Milky Way — sometimes the stars are so closely packed they’re a million times more dense than in the outer
suburb of the galaxy where we live. If there was a burst
of star formation in this area a few million years ago, it could have created
the surge of gas needed to in turn create the Fermi bubbles.
It took us until 2010 to see these Fermi bubbles
because the sky is filled with a fog of other gamma rays that can obscure our
view. This fog is created when particles
moving near light speed bump into gas, dust, and light in the Milky Way. These
collisions produce gamma rays, and scientists had to factor out the fog to
unveil the bubbles.
Just about every galaxy the size of our Milky Way (or bigger) has a supermassive black hole at its center. These objects are ginormous — hundreds of thousands to billions of times the mass of the Sun! Now, we know galaxies merge from time to time, so it follows that some of their black holes should combine too. But we haven’t seen a collision like that yet, and we don’t know exactly what it would look like.
A new simulation created on the Blue Waters supercomputer — which can do 13 quadrillion calculations per second, 3 million times faster than the average laptop — is helping scientists understand what kind of light would be produced by the gas around these systems as they spiral toward a merger.
The new simulation shows most of the light produced around these two black holes is UV or X-ray light. We can’t see those wavelengths with our own eyes, but many telescopes can. Models like this could tell the scientists what to look for.
You may have spotted the blank circular region between the two black holes. No, that’s not a third black hole. It’s a spot that wasn’t modeled in this version of the simulation. Future models will include the glowing gas passing between the black holes in that region, but the researchers need more processing power. The current version already required 46 days!
The supermassive black holes have some pretty nifty effects on the light created by the gas in the system. If you view the simulation from the side, you can see that their gravity bends light like a lens. When the black holes are lined up, you even get a double lens!
But what would the view be like from between two black holes? In the 360-degree video above, the system’s gas has been removed and the Gaia star catalog has been added to the background. If you watch the video in the YouTube app on your phone, you can moved the screen around to explore this extreme vista. Learn more about the new simulation here.
Exactly sixty years ago today, we opened our doors for the first time. And since then, we have opened up a universe of discovery and innovation.
There are so many achievements to celebrate from the past six decades, there’s no way we can go through all of them. If you want to dive deeper into our history of exploration, check out NASA: 60 Years and Counting.
In the meantime, take a moonwalk down memory lane with us while we remember a few of our most important accomplishments from the past sixty years!
In 1958, President Eisenhower signed the National Aeronautics and Space Act, which effectively created our agency. We officially opened for business on October 1.
To learn more about the start of our space program, watch our video: How It All Began.
Alongside the U.S. Air Force, we implemented the X-15 hypersonic aircraft during the 1950s and 1960s to improve aircraft and spacecraft.
The X-15 is capable of speeds exceeding Mach 6 (4,500 mph) at altitudes of 67 miles, reaching the very edge of space.
Dubbed the “finest and most productive research aircraft ever seen,” the X-15 was officially retired on October 24, 1968. The information collected by the X-15 contributed to the development of the Mercury, Gemini, Apollo, and Space Shuttle programs.
On July 20, 1969, Neil Armstrong and Buzz Aldrin became the first humans to walk on the moon. The crew of Apollo 11 had the distinction of completing the first return of soil and rock samples from beyond Earth.
Astronaut Gene Cernan, during Apollo 17, was the last person to have walked on the surface of the moon. (For now!)
The Lunar Roving Vehicle was a battery-powered rover that the astronauts used during the last three Apollo missions.
To learn more about other types of technology that we have either invented or improved, watch our video: Trailblazing Technology.
Our long-term Earth-observing satellite program began on July 23, 1972 with the launch of Landsat 1, the first in a long series (Landsat 9 is expected to launch in 2020!) We work directly with the U.S. Geological Survey to use Landsat to monitor and manage resources such as food, water, and forests.
Landsat data is one of many tools that help us observe in immense detail how our planet is changing. From algae blooms to melting glaciers to hurricane flooding, Landsat is there to help us understand our own planet better.
Off the Earth, for the Earth.
To learn more about how we contribute to the Earth sciences, watch our video: Home, Sweet Home.
Space Transportation System-1, or STS-1, was the first orbital spaceflight of our Space Shuttle program.
The first orbiter, Columbia, launched on April 12, 1981. Over the next thirty years, Challenger, Discovery, Atlantis, and Endeavour would be added to the space shuttle fleet.
Together, they flew 135 missions and carried 355 people into space using the first reusable spacecraft.
On January 16, 1978, we selected a class of 35 new astronauts–including the first women and African-American astronauts.
And on June 18, 1983, Sally Ride became the first American woman to enter space on board Challenger for STS-7.
Everybody loves Hubble! The Hubble Space Telescope was launched into orbit on April 24, 1990, and has been blowing our minds ever since.
Hubble has not only captured stunning views of our distant stars and galaxies, but has also been there for once-in-a-lifetime cosmic events. For example, on January 6, 2010, Hubble captured what appeared to be a head-on collision between two asteroids–something no one has ever seen before.
In this image, Hubble captures the Carina Nebula illuminating a three-light-year tall pillar of gas and dust.
To learn more about how we have contributed to our understanding of the solar system and beyond, watch our video: What’s Out There?
Cooperation to build the International Space Station began in 1993 between the United States, Russia, Japan, and Canada.
The dream was fully realized on November 2, 2000, when Expedition 1 crew members boarded the station, signifying humanity’s permanent presence in space!
Although the orbiting lab was only a couple of modules then, it has grown tremendously since then!
This spectacular image, the first released
using all four of TESS’ cameras, shows the satellite’s full field of view. It
captures parts of a dozen constellations, from Capricornus
(the Sea Goat) to Pictor
(the Painter’s Easel) — though it might be hard to find familiar constellations
among all these stars! The image even includes the Large and Small Magellanic
Clouds, our galaxy’s two largest companion galaxies.
The science community calls this image “first
light,” but don’t let that fool you — TESS has been seeing light since it
launched in April. A first light image like this is released to show off the
first science-quality image taken after a mission starts collecting science
data, highlighting a spacecraft’s capabilities.
After nearly a month in space, the satellite
passed about 5,000 miles from the Moon, whose gravity gave it the boost it needed to get into a special orbit
that will keep it stable and maximize its view of the sky.
During those first few weeks, we also got a
sneak peek of the sky through one of TESS’s four cameras. This test image
captured over 200,000 stars in just two seconds! The spacecraft was pointed
toward the constellation Centaurus when it snapped this picture. The bright
Centauri is visible at the lower left edge, and the edge
of the Coalsack
Nebula is in the right upper corner.
After settling into orbit, scientists ran a
number of checks on TESS, including testing its ability to collect a set of
stable images over a prolonged period of time. TESS not only proved its ability
to perform this task, it also got a surprise! A comet named C/2018 N1 passed through TESS’s cameras
for about 17 hours in July.
The images show a treasure
trove of cosmic curiosities. There are some stars whose
brightness changes over time and asteroids visible as small moving white dots.
You can even see an arc of stray light from Mars, which is located outside the
image, moving across the screen.
Now that TESS has settled into orbit and has
been thoroughly tested, it’s digging into its main mission of finding planets around other stars.
How will it spot something as tiny and faint as a planet trillions of miles
away? The trick is to look at the star!
So far, most
of the exoplanets we’ve found were detected by looking
for tiny dips in the brightness of their host stars. These dips are caused by
the planet passing between us and its star – an event called a transit. Over
its first two years, TESS will stare at 200,000 of the nearest and brightest stars
in the sky to look for transits to identify stars with planets.
TESS will be building on the legacy of NASA’s Kepler spacecraft, which also used
transits to find exoplanets. TESS’s target stars are about 10 times closer than
Kepler’s, so they’ll tend to be brighter. Because they’re closer and brighter,
TESS’s target stars will be ideal candidates for follow-up studies with current
and future observatories.
TESS is challenging over 200,000 of our
stellar neighbors to a staring contest! Who knows what new amazing planets
Outstanding views Venus, Jupiter, Saturn and Mars with the naked eye!
You’ll have to look quickly after sunset to catch Venus. And through binoculars or a telescope, you’ll see Venus’s phase change dramatically during September – from nearly half phase to a larger thinner crescent!
Jupiter, Saturn and Mars continue their brilliant appearances this month. Look southwest after sunset.
Use the summer constellations help you trace the Milky Way.
Sagittarius: where stars and some brighter clumps appear as steam from the teapot.
Aquila: where the Eagle’s bright Star Altair, combined with Cygnus’s Deneb, and Lyra’s Vega mark the Summer Triangle.
Cassiopeia, the familiar “w”- shaped constellation completes the constellation trail through the Summer Milky Way. Binoculars will reveal double stars, clusters and nebulae.
Between September 12th and the 20th, watch the Moon pass from near Venus, above Jupiter, to the left of Saturn and finally above Mars!
Both Neptune and brighter Uranus can be spotted with some help from a telescope this month.
Look at about 1:00 a.m. local time or later in the southeastern sky. You can find Mercury just above Earth’s eastern horizon shortly before sunrise. Use the Moon as your guide on September 7 and 8th.
And although there are no major meteor showers in September, cometary dust appears in another late summer sight, the morning Zodiacal light. Try looking for it in the east on moonless mornings very close to sunrise. To learn more about the Zodiacal light, watch “What’s Up” from March 2018.
The Perseid meteor shower is the best of the year! It peaks on a Moonless summer night from 4 p.m. EST on August 12 until 4 a.m. EST on August 13.
Because the new Moon falls near the peak night, the days before and after the peak will also provide nice, dark skies. Your best window of observation is from a few hours after twilight until dawn, on the days surrounding the peak.
Unlike most meteor showers, which have a short peak of high meteor rates, the Perseids have a very broad peak, as Earth takes more than three weeks to plow through the wide trail of cometary dust from comet Swift-Tuttle.
The Perseids appear to radiate from the constellation Perseus, visible in the northern sky soon after sunset this time of year. Observers in mid-northern latitudes will have the best views.
You should be able to see some meteors from July 17 to August 24, with the rates increasing during the weeks before August 12 and decreasing after August 13.
Observers should be able to see between 60 and 70 per hour at the peak. Remember, you don’t have to look directly at the constellation to see them. You can look anywhere you want to-even directly overhead.
Meteor showers like the Perseids are caused by streams of meteoroids hitting Earth’s atmosphere. The particles were once part of their parent comet-or, in some cases, from an asteroid.
The parade of planets Venus, Jupiter, Saturn and Mars–and the Milky Way continue to grace the evening sky, keeping you and the mosquitoes company while you hunt for meteors.
In Hollywood blockbusters, explosions and eruptions are often among the stars of the show. In space, explosions, eruptions and twinkling of actual stars are a focus for scientists who hope to better understand their births, lives, deaths and how they interact with their surroundings. Spend some of your Fourth of July taking a look at these celestial phenomenon:
This object became a sensation in the astronomical community when a team of researchers pointed at it with our Chandra X-ray Observatory telescope in 1901, noting that it suddenly appeared as one of the brightest stars in the sky for a few days, before gradually fading away in brightness. Today, astronomers cite it as an example of a “classical nova,” an outburst produced by a thermonuclear explosion on the surface of a white dwarf star, the dense remnant of a Sun-like star.
The brilliant tapestry of young stars flaring to life resemble a glittering fireworks display. The sparkling centerpiece is a giant cluster of about 3,000 stars called Westerlund 2, named for Swedish astronomer Bengt Westerlund who discovered the grouping in the 1960s. The cluster resides in a raucous stellar breeding ground located 20,000 light-years away from Earth in the constellation Carina.
Sometimes during solar magnetic events, solar explosions hurl clouds of magnetized particles into space. Traveling more than a million miles per hour, these coronal mass ejections, or CMEs, made up of hot material called plasma take up to three days to reach Earth. Spacecraft and satellites in the path of CMEs can experience glitches as these plasma clouds pass by. In near-Earth space, magnetic reconnection incites explosions of energy driving charged solar particles to collide with atoms in Earth’s upper atmosphere. We see these collisions near Earth’s polar regions as the aurora. Three spacecraft from our Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission, observed these outbursts known as substorms.
Every galaxy has a black hole at its center. Usually they are quiet, without gas accretions, like the one in our Milky Way. But if a star creeps too close to the black hole, the gravitational tides can rip away the star’s gaseous matter. Like water spinning around a drain, the gas swirls into a disk around the black hole at such speeds that it heats to millions of degrees. As an inner ring of gas spins into the black hole, gas particles shoot outward from the black hole’s polar regions. Like bullets shot from a rifle, they zoom through the jets at velocities close to the speed of light. Astronomers using our Hubble Space Telescope observed correlations between supermassive black holes and an event similar to tidal disruption, pictured above in the Centaurus A galaxy.
Supernovae can occur one of two ways. The first occurs when a white dwarf—the remains of a dead star—passes so close to a living star that its matter leaks into the white dwarf. This causes a catastrophic explosion. However most people understand supernovae as the death of a massive star. When the star runs out of fuel toward the end of its life, the gravity at its heart sucks the surrounding mass into its center. At the turn of the 19th century, the binary star system Eta Carinae was faint and undistinguished. Our Hubble Telescope captured this image of Eta Carinae, binary star system. The larger of the two stars in the Eta Carinae system is a huge and unstable star that is nearing the end of its life, and the event that the 19th century astronomers observed was a stellar near-death experience. Scientists call these outbursts supernova impostor events, because they appear similar to supernovae but stop just short of destroying their star.
An Eye-Catching Eruption
Extremely energetic objects permeate the universe. But close to home, the Sun produces its own dazzling lightshow, producing the largest explosions in our solar system and driving powerful solar storms.. When solar activity contorts and realigns the Sun’s magnetic fields, vast amounts of energy can be driven into space. This phenomenon can create a sudden flash of light—a solar flare.The above picture features a filament eruption on the Sun, accompanied by solar flares captured by our Solar Dynamics Observatory.