Today We Successfully Tested One Of Our RS-25 Engines, Four Of Which Will Help Power Our Space Launch

What's That Space Rock?

The path through the solar system is a rocky road. Asteroids, comets, Kuiper Belt Objects—all kinds of small bodies of rock, metal and ice are in constant motion as they orbit the Sun. But what’s the difference between them, anyway? And why do these miniature worlds fascinate space explorers so much? The answer is profound: they may hold the keys to better understanding where we all come from. Here’s 10 things to know about the solar system this week:

This picture of Eros, the first of an asteroid taken from an orbiting spacecraft, came from our NEAR mission in February 2000. Image credit: NASA/JPL

1. Asteroids

Asteroids are rocky, airless worlds that orbit our Sun. They are remnants left over from the formation of our solar system, ranging in size from the length of a car to about as wide as a large city. Asteroids are diverse in composition; some are metallic while others are rich in carbon, giving them a coal-black color. They can be “rubble piles,” loosely held together by their own gravity, or they can be solid rocks.

Most of the asteroids in our solar system reside in a region called the main asteroid belt. This vast, doughnut-shaped ring between the orbits of Mars and Jupiter contains hundreds of thousands of asteroids, maybe millions. But despite what you see in the movies, there is still a great deal of space between each asteroid. With all due respect to C3PO, the odds of flying through the asteroid belt without colliding with one are actually pretty good.

Other asteroids (and comets) follow different orbits, including some that enter Earth’s neighborhood. These are called near-Earth objects, or NEOs. We can actually keep track of the ones we have discovered and predict where they are headed. The Minor Planet Center (MPC) and Jet Propulsion Laboratory’s Center for Near Earth Object Studies (CNEOS) do that very thing. Telescopes around the world and in space are used to spot new asteroids and comets, and the MPC and CNEOS, along with international colleagues, calculate where those asteroids and comets are going and determine whether they might pose any impact threat to Earth.

For scientists, asteroids play the role of time capsules from the early solar system, having been preserved in the vacuum of space for billions of years. What’s more, the main asteroid belt may have been a source of water—and organic compounds critical to life—for the inner planets like Earth.

The nucleus of Comet 67P/Churyumov-Gerasimenko, as seen in January 2015 by the European Space Agency’s Rosetta spacecraft. Image credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

2. Comets

Comets also orbit the Sun, but they are more like snowballs than space rocks. Each comet has a center called a nucleus that contains icy chunks of frozen gases, along with bits of rock and dust. When a comet’s orbit brings it close to the Sun, the comet heats up and spews dust and gases, forming a giant, glowing ball called a coma around its nucleus, along with two tails – one made of dust and the other of excited gas (ions). Driven by a constant flow of particles from the Sun called the solar wind, the tails point away from the Sun, sometimes stretching for millions of miles.

While there are likely billions of comets in the solar system, the current confirmed number is 3,535. Like asteroids, comets are leftover material from the formation of our solar system around 4.6 billion years ago, and they preserve secrets from the earliest days of the Sun’s family. Some of Earth’s water and other chemical constituents could have been delivered by comet impacts.

An artist re-creation of a collision in deep space. Image credit: NASA/JPL-Caltech

3. Meteoroids

Meteoroids are fragments and debris in space resulting from collisions among asteroids, comets, moons and planets. They are among the smallest “space rocks.” However, we can actually see them when they streak through our atmosphere in the form of meteors and meteor showers.

This photograph, taken by an astronaut aboard the International Space Station, provides the unusual perspective of looking down on a meteor as it passes through the atmosphere. The image was taken on Aug. 13, 2011, during the Perseid meteor shower that occurs every August. Image credit: NASA

4. Meteors

Meteors are meteoroids that fall through Earth’s atmosphere at extremely high speeds. The pressure and heat they generate as they push through the air causes them to glow and create a streak of light in the sky. Most burn up completely before touching the ground. We often refer to them as “shooting stars.” Meteors may be made mostly of rock, metal or a combination of the two.

Scientists estimate that about 48.5 tons (44,000 kilograms) of meteoritic material falls on Earth each day.

The constellation Orion is framed by two meteors during the Perseid shower on Aug. 12, 2018 in Cedar Breaks National Monument, Utah. Image credit: NASA/Bill Dunford

5. Meteor Showers

Several meteors per hour can usually be seen on any given night. Sometimes the number increases dramatically—these events are termed meteor showers. They occur when Earth passes through trails of particles left by comets. When the particles enter Earth’s atmosphere, they burn up, creating hundreds or even thousands of bright streaks in the sky. We can easily plan when to watch meteor showers because numerous showers happen annually as Earth’s orbit takes it through the same patches of comet debris. This year’s Orionid meteor shower peaks on Oct. 21.

An SUV-sized asteroid, 2008TC#, impacted on Oct. 7, 2008, in the Nubian Desert, Northern Sudan. Dr. Peter Jenniskens, NASA/SETI, joined Muawia Shaddas of the University of Khartoum in leading an expedition on a search for samples. Image credit: NASA/SETI/P. Jenniskens

6. Meteorites

Meteorites are asteroid, comet, moon and planet fragments (meteoroids) that survive the heated journey through Earth’s atmosphere all the way to the ground. Most meteorites found on Earth are pebble to fist size, but some are larger than a building.

Early Earth experienced many large meteorite impacts that caused extensive destruction. Well-documented stories of modern meteorite-caused injury or death are rare. In the first known case of an extraterrestrial object to have injured a human being in the U.S., Ann Hodges of Sylacauga, Alabama, was severely bruised by a 8-pound (3.6-kilogram) stony meteorite that crashed through her roof in November 1954.

The largest object in the asteroid belt is actually a dwarf planet, Ceres. This view comes from our Dawn mission. The color is approximately as it would appear to the eye. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

7. Dwarf Planets

Don’t let the name fool you; despite their small size, dwarf planets are worlds that are just as compelling as their larger siblings. Dwarf planets are defined by astronomers as bodies massive enough to be shaped by gravity into a round or nearly round shape, but they don’t have enough of their own gravitational muscle to clear their path of other objects as they orbit the Sun. In our solar system, dwarf planets are mostly found in the Kuiper Belt beyond Neptune; Pluto is the best-known example. But the largest object in the asteroid belt is the dwarf planet Ceres. Like Pluto, Ceres shows signs of active geology, including ice volcanoes.

8. Kuiper Belt Objects

The Kuiper Belt is a disc-shaped region beyond Neptune that extends from about 30 to 55 astronomical units -- that is, 30 to 55 times the distance from the Earth to the Sun. There may be hundreds of thousands of icy bodies and a trillion or more comets in this distant region of our solar system.

An artist's rendition of the New Horizons spacecraft passing by the Kuiper Belt Object MU69 in January 2019. Image credits: NASA/JHUAPL/SwRI

Besides Pluto, some of the mysterious worlds of the Kuiper Belt include Eris, Sedna, Quaoar, Makemake and Haumea. Like asteroids and comets, Kuiper Belt objects are time capsules, perhaps kept even more pristine in their icy realm.

This chart puts solar system distances in perspective. The scale bar is in astronomical units (AU), with each set distance beyond 1 AU representing 10 times the previous distance. One AU is the distance from the Sun to the Earth, which is about 93 million miles or 150 million kilometers. Neptune, the most distant planet from the Sun, is about 30 AU. Image credit: NASA/JPL-Caltech

9. Oort Cloud Objects

The Oort Cloud is a group of icy bodies beginning roughly 186 billion miles (300 billion kilometers) away from the Sun. While the planets of our solar system orbit in a flat plane, the Oort Cloud is believed to be a giant spherical shell surrounding the Sun, planets and Kuiper Belt Objects. It is like a big, thick bubble around our solar system. The Oort Cloud’s icy bodies can be as large as mountains, and sometimes larger.

This dark, cold expanse is by far the solar system’s largest and most distant region. It extends all the way to about 100,000 AU (100,000 times the distance between Earth and the Sun) – a good portion of the way to the next star system. Comets from the Oort Cloud can have orbital periods of thousands or even millions of years. Consider this: At its current speed of about a million miles a day, our Voyager 1 spacecraft won’t reach the Oort Cloud for more than 300 years. It will then take about 30,000 years for the spacecraft to traverse the Oort Cloud, and exit our solar system entirely.

This animation shows our OSIRIS-REx spacecraft collecting a sample of the asteroid Bennu, which it is expected to do in 2020. Image credit: NASA/Goddard Space Flight Center

10. The Explorers

Fortunately, even though the Oort Cloud is extremely distant, most of the small bodies we’ve been discussing are more within reach. In fact, NASA and other space agencies have a whole flotilla of robotic spacecraft that are exploring these small worlds up close. Our mechanical emissaries act as our eyes and hands in deep space, searching for whatever clues these time capsules hold.

A partial roster of our current or recent missions to small, rocky destinations includes:

OSIRIS-REx – Now approaching the asteroid Bennu, where it will retrieve a sample in 2020 and return it to the Earth for close scrutiny.

New Horizons – Set to fly close to MU69 or “Ultima Thule,” an object a billion miles past Pluto in the Kuiper Belt on Jan. 1, 2019. When it does, MU69 will become the most distant object humans have ever seen up close.

Psyche – Planned for launch in 2022, the spacecraft will explore a metallic asteroid of the same name, which may be the ejected core of a baby planet that was destroyed long ago.

Lucy – Slated to investigate two separate groups of asteroids, called Trojans, that share the orbit of Jupiter – one group orbits ahead of the planet, while the other orbits behind. Lucy is planned to launch in 2021.

Dawn – Finishing up a successful seven-year mission orbiting planet-like worlds Ceres and Vesta in the asteroid belt.

Plus these missions from other space agencies:

The Japan Aerospace Exploration Agency (JAXA)’s Hayabusa2– Just landed a series of small probes on the surface of the asteroid Ryugu.

The European Space Agency (ESA)’s Rosetta – Orbited the comet 67P/Churyumov-Gerasimenko and dispatched a lander to its surface.

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Solar System: 5 Things To Know This Week

Our solar system is huge, so let us break it down for you. Here are 5 things to know this week: 

1. Make a Wish

The annual Leonids meteor shower is not known for a high number of "shooting stars" (expect as many as 15 an hour), but they're usually bright and colorful. They're fast, too: Leonids travel at speeds of 71 km (44 miles) per second, which makes them some of the fastest. This year the Leonids shower will peak around midnight on Nov. 17-18. The crescent moon will set before midnight, leaving dark skies for watching. Get more viewing tips HERE.

2. Back to the Beginning

Our Dawn mission to the dwarf planet Ceres is really a journey to the beginning of the solar system, since Ceres acts as a kind of time capsule from the formation of the asteroid belt. If you'll be in the Washington DC area on Nov. 19, you can catch a presentation by Lucy McFadden, a co-investigator on the Dawn mission, who will discuss what we've discovered so far at this tiny but captivating world. Find out how to attend HERE. 

3. Keep Your Eye on This Spot

The Juno spacecraft is on target for a July 2016 arrival at the giant planet Jupiter. But right now, your help is needed. Members of the Juno team are calling all amateur astronomers to upload their telescopic images and data of Jupiter. This will help the team plan their observations. Join in HERE.

4. The Ice Volcanoes of Pluto

The more data from July's Pluto flyby that comes down from the New Horizons spacecraft, the more interesting Pluto becomes. The latest finding? Possible ice volcanoes. Using images of Pluto's surface to make 3-D topographic maps, scientists discovered that some mountains on Pluto, such as the informally named Piccard Mons and Wright Mons, had structures that suggested they could be cryovolcanoes that may have been active in the recent geological past.

5. Hidden Storm

Cameras aboard the Cassini spacecraft have been tracking an impressive cloud hovering over the south pole of Saturn's moon Titan. But that cloud has turned out to be just the tip of the iceberg. A much more massive ice cloud system has been found lower in the stratosphere, peaking at an altitude of about 124 miles (200 kilometers).

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Spacewalk complete and new astronaut record set! Shane Kimbrough and Peggy Whitson of NASA successfully reconnected cables and electrical connections on an adapter-3 that will provide the pressurized interface between the station and the second of two international docking adapters to be delivered to the complex to support the dockings of U.S. commercial crew spacecraft in the future. The duo were also tasked with installing four thermal protection shields on the Tranquility module of the International Space Station.

 Having completed her eighth spacewalk, Whitson now holds the record for the most spacewalks and accumulated time spacewalking by a female astronaut. Spacewalkers have now spent a total of 1,243 hours and 42 minutes outside the station during 199 spacewalks in support of assembly and maintenance of the orbiting laboratory.

 Astronaut Thomas Pesquet of ESA posted this image and wrote, ' Shane and Peggy on their way to their first #spacewalk tasks.'

 Credit: ESA/NASA

The Hunt for New Worlds Continues with TESS

We're getting ready to start our next mission to find new worlds! The Transiting Exoplanet Survey Satellite (TESS) will find thousands of planets beyond our solar system for us to study in more detail. It's preparing to launch from our Kennedy Space Center at Cape Canaveral in Florida.

Once it launches, TESS will look for new planets that orbit bright stars relatively close to Earth. We're expecting to find giant planets, like Jupiter, but we're also predicting we'll find Earth-sized planets. Most of those planets will be within 300 light-years of Earth, which will make follow-up studies easier for other observatories.

TESS will find these new exoplanets by looking for their transits. A transit is a temporary dip in a star's brightness that happens with predictable timing when a planet crosses between us and the star. The information we get from transits can tell us about the size of the planet relative to the size of its star. We've found nearly 3,000 planets using the transit method, many with our Kepler space telescope. That's over 75% of all the exoplanets we've found so far!

TESS will look at nearly the entire sky (about 85%) over two years. The mission divides the sky into 26 sectors. TESS will look at 13 of them in the southern sky during its first year before scanning the northern sky the year after.

What makes TESS different from the other planet-hunting missions that have come before it? The Kepler mission (yellow) looked continually at one small patch of sky, spotting dim stars and their planets that are between 300 and 3,000 light-years away. TESS (blue) will look at almost the whole sky in sections, finding bright stars and their planets that are between 30 and 300 light-years away.

TESS will also have a brand new kind of orbit (visualized below). Once it reaches its final trajectory, TESS will finish one pass around Earth every 13.7 days (blue), which is half the time it takes for the Moon (gray) to orbit. This position maximizes the amount of time TESS can stare at each sector, and the satellite will transmit its data back to us each time its orbit takes it closest to Earth (orange).

Kepler's goal was to figure out how common Earth-size planets might be. TESS's mission is to find exoplanets around bright, nearby stars so future missions, like our James Webb Space Telescope, and ground-based observatories can learn what they're made of and potentially even study their atmospheres. TESS will provide a catalog of thousands of new subjects for us to learn about and explore.

The TESS mission is led by MIT and came together with the help of many different partners. Learn more about TESS and how it will further our knowledge of exoplanets, or check out some more awesome images and videos of the spacecraft. And stay tuned for more exciting TESS news as the spacecraft launches!

Watch the Launch!

*April 16 Update*

Launch teams are standing down today to conduct additional Guidance Navigation and Control analysis, and teams are now working towards a targeted launch of the Transiting Exoplanet Survey Satellite (TESS) on Wednesday, April 18. The TESS spacecraft is in excellent health, and remains ready for launch. TESS will launch on a Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida.

For more information and updates, visit: https://blogs.nasa.gov/tess/

Live Launch Coverage!

TESS is now slated to launch on Wednesday, April 18 on a SpaceX Falcon 9 rocket from our Kennedy Space Center in Florida.

Watch HERE.

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@manishkumarmishra: How does all this work benefit us back here on Earth?

Freaky fast and really awesome! NASA astronaut Jack Fischer posted this GIF to his social media Tuesday saying, “I was checking the view out the back window & decided to take a pic so you can see proof of our ludicrous speed! #SpaceIsAwesome”.

In case you didn’t know, the International Space Station travels 17,500 miles per hour as it orbits 250 miles above the Earth.

Currently, three humans are living and working there, conducting important science and research. The orbiting laboratory is home to more than 250 experiments, including some that are helping us determine the effects of microgravity on the human body. Research on the station will not only help us send humans deeper into space than ever before, including to Mars, but also benefits life here on Earth.

Follow NASA astronaut Jack Fischer on Instagram and Twitter. 

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Ever wanted to ask a NASA astronaut a question? Here’s your chance!

NASA astronaut Kate Rubins will be taking your questions in an Answer Time session on Thursday, October 17 from 12pm - 1pm ET here on NASA’s Tumblr! Find out what it’s like to live and work 254 miles above our planet’s surface. Make sure to ask your question now by visiting http://nasa.tumblr.com/ask!

Dr. Kate Rubins was selected in 2009 as one of nine members of the 20th NASA astronaut class. She holds a Bachelor of Science degree in Molecular Biology and a Ph.D. in Cancer Biology. During her first spaceflight from July - October 2016 as a member of the Expedition 49 and 50 crew, Dr. Rubins made history by becoming the first person to sequence DNA in space. She also worked on the Heart Cells Experiment which studied how heart muscle tissues contract, grow and change in microgravity. Before becoming a NASA astronaut, Dr. Rubins worked with some of the world’s most dangerous pathogens, heading 14 researchers studying viral diseases that primarily affect Central and West Africa. 

Dr. Kate Rubins Fun Facts

Dr. Rubins and colleagues developed the first model of smallpox infection.

She conducted her undergraduate research on HIV-1 integration in the Infectious Diseases Laboratory at the Salk Institute for Biological Studies. 

She conducted research on filoviruses (Ebola and Marburg), Arenaviruses (Lassa Fever) and collaborative projects with the U.S. Army to develop therapies for Ebola and Lassa viruses. 

She has logged 115 days in space and 12 hours and 46 minutes of spacewalk time.

She enjoys running, cycling, swimming, flying, scuba diving and reading. 

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com. 

Answer Time from Space!

I’m on day 321 of my #YearInSpace, and today I surpassed 500 days in space total. Let’s chat! Sat., Feb. 13 at 1:45 p.m. ET. 

Things You Might Not Know About Our Sun

The sun is a star, a hot ball of glowing gases at the heart of our solar system. Its influence extends far beyond the orbits of distant Neptune and Pluto. Without the sun’s intense energy and heat, there would be no life on Earth. And though it is special to us, there are billions of stars like our sun scattered across the Milky Way galaxy.

Impress Your Friends with These Sun Facts:

If the sun were as tall as a typical front door, the Earth would be the size of a U.S. nickel

The temperature at the sun’s core is about 27 million degrees Fahrenheit

Our sun is more massive than the average star in its neighborhood. Nearly 90% of stars are less massive, making them cooler and dimmer

The sun contains 99.9% of all matter in our solar system

During a single second, the sun converts 4 million tons of matter to pure energy

It would take about 1 million Earths to fill the sun if it were a hollow ball

The sun rotates on its axis approximately once every 27 days

The sun is 93 million miles away from Earth and is almost 5 billion years old

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Benefits To Humanity

How does research in space help life on Earth? That’s a great question! It seems crazy that a laboratory orbiting about 200 miles over us can have a benefits on science on the ground. Here are a few ways that research aboard the International Space Station benefits humanity:

Improve Human Health

The space station has supported research that supports areas such as aging, trauma, disease and the environment. Advances in human health have been gained from the unique microgravity environment.

For example, crew aboard the station experience issues such as bone loss while in space. Learning about the causes and understanding the treatments can help the elderly or people prone to Osteoporosis here on Earth.

Are you Asthmatic? Crew aboard the space station use a tool that could be used for Asthma patients. The lightweight, easy-to-use device is used to monitor levels of asthma control and the efficiency of medication. This leads to more accurate dosing, reduced attacks and improved quality of life.

Drinkable water on the space station isn’t something just sitting in water bottles waiting to be consumed. Since storage and weight are limited in transporting things to space, crew members must recycle old, dirty water and reuse it day after day. The technology they use for this on the space station, can also be used in at-risk areas on Earth that don’t have access to clean water.

Earth Observations

The International Space Station has a unique vantage point for observing Earth’s ecosystems. A wide variety of payloads can be attached to the station’s exterior to collect data on things like: global climate, environmental change and natural hazards.

Farming from Space

Farmers can leverage images from the International Space Station to grow crops. The camera captures frequent images of Earth in visible and infrared light, that helps farmers monitor crop growth for disease or fertility differences.

From NASA to Napa. Some of the research on the space station has even provided benefits to the wine industry on Earth! Solutions for growing crops in space translates really well to solutions for mold prevention in wine cellars and other confined spaces on Earth.

For many other ways that research on the International Space Station benefits life on Earth, go HERE.

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