Science Headdesk

Our sun is dynamic and ever-changing. On Friday, July 14, a solar flare and a coronal mass ejection erupted from the same, large active region. The coils arcing over this active region are particles spiraling along magnetic field lines.

Solar flares are explosions on the sun that send energy, light and high-speed particles into space. Such flares are often associated with solar magnetic storms known as coronal mass ejections. While these are the most common solar events, the sun can also emit streams of very fast protons – known as solar energetic particle (SEP) events – and disturbances in the solar wind known as corotating interaction regions (CIRs).

Learn more HERE.

Swirling bands of light and dark clouds on Jupiter are seen in this image made by citizen scientists using data from our Juno spacecraft. Each of the alternating light and dark atmospheric bands in this image is wider than Earth, and each rages around Jupiter at hundreds of miles (km) per hour. The lighter areas are regions where gas is rising, and the darker bands are regions where gas is sinking. This image was acquired on May 19, 2017 from about 20,800 miles (33,400km) above Jupiter’s cloud tops. Learn more

Credits: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstädt /Seán Doran

This 100-Million-Year-Old Bird Trapped in Amber Is The Best We’ve Ever Seen

Scientists have uncovered an incredible specimen in Myanmar that has given us a glimpse of life from 100 million years ago - a piece of amber containing the remarkably preserved remains of an ancient bird hatchling.

Inside the amber, you can make out the head, tail, and neck of the bird, but it’s the wings and feet that are the real marvels - the chunk of fossilised tree resin has perfectly preserved the bird’s feathers, flesh, and claws, and gives us insight into a doomed group of prehistoric species called the ‘opposite birds’.

“It’s the most complete and detailed view we’ve ever had,” one of the team behind the discovery, Ryan McKellar from the Royal Saskatchewan Museum in Canada, told New Scientist.

“Seeing something this complete is amazing. It’s just stunning.”

Our Juno spacecraft has just released some exciting new science from its first close flyby of Jupiter! 

In case you don’t know, the Juno spacecraft entered orbit around the gas giant on July 4, 2016…about a year ago. Since then, it has been collecting data and images from this unique vantage point.

Juno is in a polar orbit around Jupiter, which means that the majority of each orbit is spent well away from the gas giant. But once every 53 days its trajectory approaches Jupiter from above its north pole, where it begins a close two-hour transit flying north to south with its eight science instruments collecting data and its JunoCam camera snapping pictures.

Space Fact: The download of six megabytes of data collected during the two-hour transit can take one-and-a-half days!

Juno and her cloud-piercing science instruments are helping us get a better understanding of the processes happening on Jupiter. These new results portray the planet as a complex, gigantic, turbulent world that we still need to study and unravel its mysteries.

So what did this first science flyby tell us? Let’s break it down…

1. Tumultuous Cyclones

Juno’s imager, JunoCam, has showed us that both of Jupiter’s poles are covered in tumultuous cyclones and anticyclone storms, densely clustered and rubbing together. Some of these storms as large as Earth!

These storms are still puzzling. We’re still not exactly sure how they formed or how they interact with each other. Future close flybys will help us better understand these mysterious cyclones. 

Seen above, waves of clouds (at 37.8 degrees latitude) dominate this three-dimensional Jovian cloudscape. JunoCam obtained this enhanced-color picture on May 19, 2017, at 5:50 UTC from an altitude of 5,500 miles (8,900 kilometers). Details as small as 4 miles (6 kilometers) across can be identified in this image.

An even closer view of the same image shows small bright high clouds that are about 16 miles (25 kilometers) across and in some areas appear to form “squall lines” (a narrow band of high winds and storms associated with a cold front). On Jupiter, clouds this high are almost certainly comprised of water and/or ammonia ice.

2. Jupiter’s Atmosphere

Juno’s Microwave Radiometer is an instrument that samples the thermal microwave radiation from Jupiter’s atmosphere from the tops of the ammonia clouds to deep within its atmosphere.

Data from this instrument suggest that the ammonia is quite variable and continues to increase as far down as we can see with MWR, which is a few hundred kilometers. In the cut-out image below, orange signifies high ammonia abundance and blue signifies low ammonia abundance. Jupiter appears to have a band around its equator high in ammonia abundance, with a column shown in orange.

Why does this ammonia matter? Well, ammonia is a good tracer of other relatively rare gases and fluids in the atmosphere…like water. Understanding the relative abundances of these materials helps us have a better idea of how and when Jupiter formed in the early solar system.

This instrument has also given us more information about Jupiter’s iconic belts and zones. Data suggest that the belt near Jupiter’s equator penetrates all the way down, while the belts and zones at other latitudes seem to evolve to other structures.

3. Stronger-Than-Expected Magnetic Field

Prior to Juno, it was known that Jupiter had the most intense magnetic field in the solar system…but measurements from Juno’s magnetometer investigation (MAG) indicate that the gas giant’s magnetic field is even stronger than models expected, and more irregular in shape.

At 7.766 Gauss, it is about 10 times stronger than the strongest magnetic field found on Earth! What is Gauss? Magnetic field strengths are measured in units called Gauss or Teslas. A magnetic field with a strength of 10,000 Gauss also has a strength of 1 Tesla.  

Juno is giving us a unique view of the magnetic field close to Jupiter that we’ve never had before. For example, data from the spacecraft (displayed in the graphic above) suggests that the planet’s magnetic field is “lumpy”, meaning its stronger in some places and weaker in others. This uneven distribution suggests that the field might be generated by dynamo action (where the motion of electrically conducting fluid creates a self-sustaining magnetic field) closer to the surface, above the layer of metallic hydrogen. Juno’s orbital track is illustrated with the black curve. 

4. Sounds of Jupiter

Juno also observed plasma wave signals from Jupiter’s ionosphere. This movie shows results from Juno’s radio wave detector that were recorded while it passed close to Jupiter. Waves in the plasma (the charged gas) in the upper atmosphere of Jupiter have different frequencies that depend on the types of ions present, and their densities. 

Mapping out these ions in the jovian system helps us understand how the upper atmosphere works including the aurora. Beyond the visual representation of the data, the data have been made into sounds where the frequencies and playback speed have been shifted to be audible to human ears.

5. Jovian “Southern Lights”

The complexity and richness of Jupiter’s “southern lights” (also known as auroras) are on display in this animation of false-color maps from our Juno spacecraft. Auroras result when energetic electrons from the magnetosphere crash into the molecular hydrogen in the Jovian upper atmosphere. The data for this animation were obtained by Juno’s Ultraviolet Spectrograph. 

During Juno’s next flyby on July 11, the spacecraft will fly directly over one of the most iconic features in the entire solar system – one that every school kid knows – Jupiter’s Great Red Spot! If anybody is going to get to the bottom of what is going on below those mammoth swirling crimson cloud tops, it’s Juno.

Stay updated on all things Juno and Jupiter by following along on social media: Twitter | Facebook | YouTube | Tumblr

Hail the Hexagon…

The full light of our sun allowed the Cassini spacecraft to capture this image of Saturn’s hexagonal polar jet stream, but the sun does not provide much warmth. In addition to being low in the sky (just like summer at Earth’s poles), the sun is nearly ten times as distant from Saturn as from Earth. This results in the sunlight being only about 1 percent as intense as at our planet. 

The view was obtained at a distance of approximately 560,000 miles (900,000 kilometers) from Saturn. Image scale is 33 miles (54 kilometers) per pixel.

More info: https://www.nasa.gov/image-feature/jpl/pia21327/hail-the-hexagon

Over a 22-hour period (May 2-3, 2017), strands of plasma at the sun’s edge shifted and twisted back and forth. In this close-up, the strands are being manipulated by strong magnetic forces associated with active regions on the sun. 

To give a sense of scale, the strands hover above the sun more than several times the size of Earth! The images were taken in a wavelength of extreme ultraviolet light. 

Learn more: http://go.nasa.gov/2qT2C4B

Credits: NASA/SDO

Our solar system is a jewel box filled with a glittering variety of beautiful worlds–and not all of them are planets. This week, we present our solar system’s most marvelous moons.

1. Weird Weather: Titan

Saturn’s hazy moon Titan is larger than Mercury, but its size is not the only way it’s like a planet. Titan has a thick atmosphere, complete with its own “water cycle” – except that it’s way too cold on Titan for liquid water. Instead, rains of liquid hydrocarbons like ethane and methane fall onto icy mountains, run into rivers, and gather into great seas. Our Cassini spacecraft mapped the methane seas with radar, and its cameras even caught a glimpse of sunlight reflecting off the seas’ surface. Learn more about Titan: saturn.jpl.nasa.gov/science/titan/

2. Icy Giant: Ganymede

Jupiter’s moon Ganymede is the largest in the solar system. It’s bigger than Mercury and Pluto, and three-quarters the size of Mars. It’s also the only moon known to have its own magnetic field. Details: solarsystem.nasa.gov/planets/ganymede/indepth

3. Retrograde Rebel: Triton

Triton is Neptune’s largest moon, and the only one in the solar system to orbit in the opposite direction of its planet’s rotation, a retrograde orbit. It may have been captured from the Kuiper Belt, where Pluto orbits. Despite the frigid temperatures there, Triton has cryovolcanic activity – frozen nitrogen sometimes sublimates directly to gas and erupts from geysers on the surface. More on Triton: solarsystem.nasa.gov/planets/triton/indepth

4. Cold Faithful: Enceladus

The most famous geysers in our solar system (outside of those on Earth) belong to Saturn’s moon Enceladus. It’s a small, icy body, but Cassini revealed this world to be one of the solar system’s most scientifically interesting destinations. Geyser-like jets spew water vapor and ice particles from an underground ocean beneath the icy crust of Enceladus. With its global ocean, unique chemistry and internal heat, Enceladus has become a promising lead in our search for worlds where life could exist. Get the details: saturn.jpl.nasa.gov/science/enceladus/

5. Volcano World: Io

Jupiter’s moon Io is subjected to tremendous gravitational forces that cause its surface to bulge up and down by as much as 330 feet (100 m). The result? Io is the most volcanically active body in the Solar System, with hundreds of volcanoes, some erupting lava fountains dozens of miles high. More on Io’s volcanoes: solarsystem.nasa.gov/planets/io/indepth

6. Yin and Yang Moon: Iapetus

When Giovanni Cassini discovered Iapetus in 1671, he observed that one side of this moon of Saturn was bright and the other dark. He noted that he could only see Iapetus on the west side of Saturn, and correctly concluded that Iapetus had one side much darker than the other side. Why? Three centuries later, the Cassini spacecraft solved the puzzle. Dark, reddish dust in Iapetus’s orbital path is swept up and lands on the leading face of the moon. The dark areas absorb energy and become warmer, while uncontaminated areas remain cooler. Learn more: saturn.jpl.nasa.gov/news/2892/cassini-10-years-at-saturn-top-10-discoveries/#nine

7. A Double World: Charon and Pluto

At half the size of Pluto, Charon is the largest of Pluto’s moons and the largest known satellite relative to its parent body. The moon is so big compared to Pluto that Pluto and Charon are sometimes referred to as a double planet system. Charon’s orbit around Pluto takes 6.4 Earth days, and one Pluto rotation (a Pluto day) takes 6.4 Earth days. So from Pluto’s point of view Charon neither rises nor sets, but hovers over the same spot on Pluto’s surface, and the same side of Charon always faces Pluto. Get the details: www.nasa.gov/feature/pluto-and-charon-new-horizons-dynamic-duo

8. “Death Star” Moon: Mimas

Saturn’s moon Mimas has one feature that draws more attention than any other: the crater Herschel, which formed in an impact that nearly shattered the little world. Herschel gives Mimas a distinctive look that prompts an oft-repeated joke. But, yes, it’s a moon. More: olarsystem.nasa.gov/planets/mimas

9. Don’t Be Afraid, It’s Just Phobos

In mythology, Mars is a the god of war, so it’s fitting that its two small moons are called Phobos, “fear,” and Deimos, “terror.” Our Mars Reconnaissance Orbiter caught this look at Phobos, which is roughly 17 miles (27 km) wide. In recent years, NASA scientists have come to think that Phobos will be torn apart by its host planet’s gravity. Details: www.nasa.gov/feature/goddard/phobos-is-falling-apart

Learn more about Phobos: solarsystem.nasa.gov/planets/phobos/indepth

10. The Moon We Know Best

Although decades have passed since astronauts last set foot on its surface, Earth’s moon is far from abandoned. Several robotic missions have continued the exploration. For example, this stunning view of the moon’s famous Tycho crater was captured by our Lunar Reconnaissance Orbiter, which continues to map the surface in fine detail today. More: www.lroc.asu.edu/posts/902

Discover more lists of 10 things to know about our solar system HERE.

This unprocessed image shows features in Saturn’s atmosphere from closer than ever before. The view was captured by our Cassini spacecraft during its first Grand Finale dive between the planet and its rings on April 26, 2017.

As Cassini dove through the gap, it came within about 1,900 miles (3,000 kilometers) of Saturn’s cloud tops (where the air pressure is 1 bar – comparable to the atmospheric pressure of Earth at sea level) and within about 200 miles (300 kilometers) of the innermost visible edge of the rings.

See all the unprocessed images from Cassini: https://saturn.jpl.nasa.gov/galleries/raw-images/ 

Cascading loops on the surface of the sun highlight an active region that had just rotated into view of our solar-observing spacecraft. We have observed this phenomenon numerous times, but this one was one of the longest and clearest sequences we have seen in years. 

The bright loops are actually charged particles spinning along the magnetic field lines! The action was captured in a combination of two wavelengths of extreme ultraviolet light over a period of about 20 hours. 

Take a closer look: https://sdo.gsfc.nasa.gov/gallery/potw/item/798

Stretched Loops: When an active region rotated over to the edge of the sun, it presented us with a nice profile view of its elongated loops stretching and swaying above it (March 8/9, 2017). These loops are actually charged particles (made visible in extreme ultraviolet light) swirling along the magnetic field lines of the active region. The video covers about 30 hours of activity. Also of note is a darker twisting mass of plasma to the left of the active region being pulled and spun about by magnetic forces.

Our Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in an area called the habitable zone, where liquid water is most likely to exist on a rocky planet.

This exoplanet system is called TRAPPIST-1, named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile. In May 2016, researchers using TRAPPIST announced they had discovered three planets in the system.

Assisted by several ground-based telescopes, Spitzer confirmed the existence of two of these planets and discovered five additional ones, increasing the number of known planets in the system to seven.

This is the FIRST time three terrestrial planets have been found in the habitable zone of a star, and this is the FIRST time we have been able to measure both the masses and the radius for habitable zone Earth-sized planets.

All of these seven planets could have liquid water, key to life as we know it, under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.

At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Because they are located outside of our solar system, these planets are scientifically known as exoplanets. To clarify, exoplanets are planets outside our solar system that orbit a sun-like star.

In this animation, you can see the planets orbiting the star, with the green area representing the famous habitable zone, defined as the range of distance to the star for which an Earth-like planet is the most likely to harbor abundant liquid water on its surface. Planets e, f and g fall in the habitable zone of the star.

Using Spitzer data, the team precisely measured the sizes of the seven planets and developed first estimates of the masses of six of them. The mass of the seventh and farthest exoplanet has not yet been estimated.

For comparison…if our sun was the size of a basketball, the TRAPPIST-1 star would be the size of a golf ball.

Based on their densities, all of the TRAPPIST-1 planets are likely to be rocky. Further observations will not only help determine whether they are rich in water, but also possibly reveal whether any could have liquid water on their surfaces.

The sun at the center of this system is classified as an ultra-cool dwarf and is so cool that liquid water could survive on planets orbiting very close to it, closer than is possible on planets in our solar system. All seven of the TRAPPIST-1 planetary orbits are closer to their host star than Mercury is to our sun.

 The planets also are very close to each other. How close? Well, if a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth’s sky.

The planets may also be tidally-locked to their star, which means the same side of the planet is always facing the star, therefore each side is either perpetual day or night. This could mean they have weather patterns totally unlike those on Earth, such as strong wind blowing from the day side to the night side, and extreme temperature changes.

Because most TRAPPIST-1 planets are likely to be rocky, and they are very close to one another, scientists view the Galilean moons of Jupiter – lo, Europa, Callisto, Ganymede – as good comparisons in our solar system. All of these moons are also tidally locked to Jupiter. The TRAPPIST-1 star is only slightly wider than Jupiter, yet much warmer. 

How Did the Spitzer Space Telescope Detect this System?

Spitzer, an infrared telescope that trails Earth as it orbits the sun, was well-suited for studying TRAPPIST-1 because the star glows brightest in infrared light, whose wavelengths are longer than the eye can see. Spitzer is uniquely positioned in its orbit to observe enough crossing (aka transits) of the planets in front of the host star to reveal the complex architecture of the system. 

Every time a planet passes by, or transits, a star, it blocks out some light. Spitzer measured the dips in light and based on how big the dip, you can determine the size of the planet. The timing of the transits tells you how long it takes for the planet to orbit the star.

The TRAPPIST-1 system provides one of the best opportunities in the next decade to study the atmospheres around Earth-size planets. Spitzer, Hubble and Kepler will help astronomers plan for follow-up studies using our upcoming James Webb Space Telescope, launching in 2018. With much greater sensitivity, Webb will be able to detect the chemical fingerprints of water, methane, oxygen, ozone and other components of a planet’s atmosphere.

At 40 light-years away, humans won’t be visiting this system in person anytime soon…that said…this poster can help us imagine what it would be like: 

A mission studying Earth’s magnetic field by flying four identical spacecraft is headed into new territory. 

The Magnetospheric Multiscale mission, or MMS, has been studying the magnetic field on the side of Earth facing the sun, the day side – but now we’re focusing on something else. On February 9, MMS started the three-month-long process of shifting to a new orbit. 

One key thing MMS studies is magnetic reconnection – a process that occurs when magnetic fields collide and re-align explosively into new positions. The new orbit will allow MMS to study reconnection on the night side of the Earth, farther from the sun.

Magnetic reconnection on the night side of Earth is thought to be responsible for causing the northern and southern lights.  

To study the interesting regions of Earth’s magnetic field on the night side, the four MMS spacecraft are being boosted into an orbit that takes them farther from Earth than ever before. Once it reaches its final orbit, MMS will shatter its previous Guinness World Record for highest altitude fix of a GPS.

To save on fuel, the orbit is slowly adjusted over many weeks. The boost to take each spacecraft to its final orbit will happen during the first week of April.

On April 19, each spacecraft will be boosted again to raise its closest approach to Earth, called perigee. Without this step, the spacecraft would be way too close for comfort – and would actually reenter Earth’s atmosphere next winter! 

The four MMS spacecraft usually fly really close together – only four miles between them – in a special pyramid formation called a tetrahedral, which allows us to examine the magnetic environment in three dimensions.

But during orbit adjustments, the pyramid shape is broken up to make sure the spacecraft have plenty of room to maneuver. Once MMS reaches its new orbit in May, the spacecraft will be realigned into their tetrahedral formation and ready to do more 3D magnetic science.

This week, we’re attending the International Consumer Electronics Show (CES), where we’re joining industrial pioneers and business leaders from across the globe to showcase our space technology. Since 1967, CES has been the place to be for next-generation innovations to get their marketplace debut.

Our technologies are driving exploration and enabling the agency’s bold new missions to extend the human presence beyond the moon, to an asteroid, to Mars and beyond. Here’s a look at five technologies we’re showing off at #CES2017:

1. IDEAS

Our Integrated Display and Environmental Awareness System (IDEAS) is an interactive optical computer that works for smart glasses. The idea behind IDEAS is to enhance real-time operations by providing augmented reality data to field engineers here on Earth and in space. 

This device would allow users to see and modify critical information on a transparent, interactive display without taking their eyes or hands off the work in front of them. 

This wearable technology could dramatically improve the user’s situational awareness, thus improving safety and efficiency. 

For example, an astronaut could see health data, oxygen levels or even environmental emergencies like “invisible” ethanol fires right on their helmet view pane. 

And while the IDEAS prototype is an innovative solution to the challenges of in-space missions, it won’t just benefit astronauts—this technology can be applied to countless fields here on Earth.

2. VERVE

Engineers at our Ames Research Center are developing robots to work as teammates with humans. 

They created a user interface called the Visual Environment for Remote Virtual Exploration (VERVE) that allows researchers to see from a robot’s perspective. 

Using VERVE, astronauts on the International Space Station remotely operated the K10 rover—designed to act as a scout during NASA missions to survey terrain and collect science data to help human explorers. 

This week, Nissan announced that a version of our VERVE was modified for its Seamless Autonomous Mobility (SAM), a platform for the integration of autonomous vehicles into our society. For more on this partnership: https://www.nasa.gov/ames/nisv-podcast-Terry-Fong

3. OnSight

Did you know that we are leveraging technology from virtual and augmented reality apps to help scientists study Mars and to help astronauts in space? 

The Ops Lab at our Jet Propulsion Laboratory is at the forefront of deploying these groundbreaking applications to multiple missions. 

One project we’re demonstrating at CES, is how our OnSight tool—a mixed reality application developed for the Microsoft HoloLens—enables scientists to “work on Mars” together from their offices. 

Supported by the Mars 2020 and Curiosity missions, it is currently in use by a pilot group of scientists for rover operations. Another HoloLens project is being used aboard the International Space Station to empower the crew with assistance when and where they need it.

At CES, we’re also using the Oculus Rift virtual reality platform to provide a tour from the launchpad at our Kennedy Space Center of our Space Launch System (SLS). SLS will be the world’s most powerful rocket and will launch astronauts in the Orion Spacecraft on missions to an asteroid and eventually to Mars. Engineers continue to make progress aimed toward delivering the first SLS rocket to Kennedy in 2018.

4. PUFFER

The Pop-Up Flat Folding Explorer Robot, PUFFER, is an origami-inspired robotic technology prototype that folds into the size of a smartphone. 

It is a low-volume, low-cost enhancement whose compact design means that many little robots could be packed in to a larger “parent” spacecraft to be deployed on a planet’s surface to increase surface mobility. It’s like a Mars rover Mini-Me!

5. ROV-E

Our Remote Operated Vehicle for Education, or ROV-E, is a six-wheeled rover modeled after our Curiosity and the future Mars 2020 Rover. 

It uses off-the-shelf, easily programmable computers and 3D-printed parts. ROV-E has four modes, including user-controlled driving to sensor-based hazard-avoidance and “follow me” modes. ROV-E can answer questions about Mars and follow voice commands.

ROV-E was developed by a team of interns and young, up-and-coming professionals at NASA’s Jet Propulsion Laboratory who wanted to build a Mars rover from scratch to help introduce students and the public to Science, Technology, Engineering & Mathematics (STEM) careers, planetary science and our Journey to Mars.

Twin spacecraft give humanity unprecedented views of the entire sun at one time, traveling to the far side of our home star over the course of a 10-year mission.

These two spacecraft are called STEREO, short for Solar and Terrestrial Relations Observatory. Launched on Oct. 25, 2006, and originally slated for a two-year mission, both spacecraft sent back data for nearly eight years, and STEREO-A still sends information and images from its point of view on the far side of the sun.

STEREO watches the sun from two completely new perspectives. It also provides information invaluable for understanding the sun and its impact on Earth, other worlds, and space itself – collectively known as space weather. On Earth, space weather can trigger things like the aurora and, in extreme cases, put a strain on power systems or damage high-flying satellites.

Because the rest of our sun-watching satellites orbit near our home planet, STEREO’s twin perspectives far from Earth give us a unique opportunity to look at solar events from all sides and understand them in three dimensions.

We use data from STEREO and other missions to understand the space environment throughout the solar system. This helps operators for missions in deep space prepare for the sudden bursts of particles and magnetic field that could pose a danger to their spacecraft. 

STEREO has also helped us understand other objects in our solar system – like comets. Watching how a comet’s tail moves gives us clues about the constant stream of particles that flows out from the sun, called the solar wind.

STEREO is an essential piece of our heliophysics fleet, which includes 17 other missions. Together, these spacecraft shed new light on the sun and its interaction with space, Earth, and other worlds throughout the solar system. 

To celebrate, we’re hosting a Facebook Live event on Wednesday, Oct. 26. Join us at noon ET on the NASA Sun Science Facebook page to learn more about STEREO and ask questions. 

Learn more about how NASA studies the sun at: www.nasa.gov/stereo

The universe suddenly looks a lot more crowded…

We already estimated that there were about 100 billion galaxies in the observable universe, but new research shows that this estimate is at least 10 times too low!

First, what is the observable universe? Well, it is the most distant part of the universe we can see from Earth because, in theory, the light from these objects have had time to reach Earth.

In a new study using surveys taken by the Hubble Space Telescope and other observatories, astronomers came to the surprising conclusion that there are at least 10 times more galaxies in the observable universe than previously thought. This places the universe’s estimated population at, minimally, 2 trillion galaxies!

The results have clear implications for galaxy formation, and also helps shed light on an ancient astronomical paradox – why is the sky dark at night?

Most of these newly discovered galaxies were relatively small and faint, with masses similar to those of the satellite galaxies surrounding the Milky Way.

Using deep-space images from the Hubble Space Telescope and other observatories, astronomers converted the images into 3-D, in order to make accurate measurements of the number of galaxies at different epochs in the universe’s history.

In addition, they used new mathematical models, which allowed them to infer the existence of galaxies that the current generation of telescopes cannot observe. This led to the surprising conclusion that in order for the numbers of galaxies we now see and their masses to add up, there must be a further 90% of galaxies in the observable universe that are too faint and too far away to be seen with present-day telescopes.

The myriad small faint galaxies from the early universe merged over time into the larger galaxies we can now observe.

That means that over 90% of the galaxies in the universe have yet to be studied! In the near future, the James Webb Space Telescope will be able to study these ultra-faint galaxies and give us more information about their existence.

So back to the question…Why is the sky dark at night if the universe contains an infinity of stars? Researchers came to the conclusion that indeed there actually is such an abundance of galaxies that, in principle, every patch in the sky contains part of a galaxy.

However, starlight from the galaxies is invisible to the human eye and most modern telescopes due to other known factors that reduce visible and ultraviolet light in the universe. Those factors are the reddening of light due to the expansion of space, the universe’s dynamic nature, and the absorption of light by intergalactic dust and gas. All combined, this keeps the night sky dark to our vision.