Reconstruction of what Earth's light curve would look like. Credit:
S. Fan et. al., arXiv (2019) arXiv:1908.04350
The study of exoplanets has matured considerably in the last ten years. During this time, the majority of the over 4000 exoplanets that are currently known to us were discovered. It was also during this time that the process has started to shift from the process of discovery to characterization. What’s more, next-generation instruments will allow for studies that will reveal a great deal about the surfaces and atmospheres of exoplanets.
This naturally raises the question: what would a sufficiently-advanced species see if they were studying our planet? Using multi-wavelength data of Earth, a team of Caltech scientists was able to construct a map of what Earth would look like to distant alien observers. Aside from addressing the itch of curiosity, this study could also help astronomers reconstruct the surface features of “Earth-like” exoplanets in the future.
This animation shows images of the far side of the moon, illuminated by the sun, as it crosses between the DISCOVR spacecraft's Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth - one million miles away. Credit: NASA/NOAA
This animation shows images of the far side of the moon, illuminated by the sun, as it crosses between the DISCOVR spacecraft’s Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth – one million miles away. Credit: NASA/NOAA
See YouTube version and EPIC camera below[/caption]
An eye-poppingly ‘EPIC’ view of the sunlit far side of the Moon transiting the sunlit side of Earth was recently captured by NASA’s Earth Polychromatic Imaging Camera (EPIC) camera from one million miles away. “Wow!” – is an understatement!
The stunning animation of the Moon crossing in front of the Earth, shown above, and seemingly unlike anything else, was created from a series of images taken in July by NASA’s EPIC camera flying aboard the orbiting Deep Space Climate Observatory (DSCOVR), a space weather monitoring satellite, according to a NASA statement.
Have just witnessed NASA’s New Horizons flyby of the Pluto-Charondouble planet system, the similarity to what some call the Earth-Moon double planet system is eerie. You could imagine ones heart going out to Earth’s Australian continent as an upside down version of Pluto’s bright heart shaped ‘Tombaugh Regio’ region in the southern hemisphere.
EPIC is a four megapixel CCD camera and telescope mounted on DSCOVR and orbiting at the L1 Lagrange Point – a neutral gravity point that lies on the direct line between Earth and the sun.
The goal of the $340 million DSCOVR is to monitor the solar wind and aid very important forecasts of space weather at Earth from L1.
EPIC will capture “a constant view of the fully illuminated Earth as it rotates, providing scientific observations of ozone, vegetation, cloud height and aerosols in the atmosphere.”
L1 is located 1.5 million kilometers (932,000 miles) sunward from Earth. At L1 the gravity between the sun and Earth is perfectly balanced and the DSCOVR satellite orbits about that spot just like a planet.
The EPIC images “were taken between 3:50 p.m. and 8:45 p.m. EDT on July 16, showing the moon moving over the Pacific Ocean near North America,” NASA said.
This image shows images of the far side of the moon, illuminated by the sun, as it crosses between the DISCOVR spacecraft’s Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth – one million miles away. Credits: NASA/NOAA
You can see Earth’s North Pole at the upper left side of the images which results from the orbital tilt of Earth from the vantage point of the spacecraft at the L1 Lagrange Point.
EPIC will take full disk color images of the sunlit side of Earth at least six times per day.
They will be made publically available by NASA at a dedicated website, when the camera starts its regular daily science observation campaign of the home planet in about a month during September.
NASA says the images will show varying views of the rotating Earth and they will be posted online some 12 to 36 hours after they are acquired.
Each image is actually a composite of three images taken in the red, green and blue channels of the EPIC camera to provide the final “natural color” image of Earth. Since the images are taken about 30 seconds apart as the moon is moving there is a slight but noticeable artifact on the right side of the moon, NASA explained.
Altogether, “ EPIC takes a series of 10 images using different narrowband spectral filters — from ultraviolet to near infrared — to produce a variety of science products. The red, green and blue channel images are used in these color images.”
EPIC should capture these Earth-Moon transits about twice per year as the orbit of DSCOVR crosses the orbital plane of the moon.
The closest analog according to NASA came in May 2008 when NASA’s Deep Impact spacecraft “captured a similar view of Earth and the moon from a distance of 31 million miles away. The series of images showed the moon passing in front of our home planet when it was only partially illuminated by the sun.”
We never see the far side of the moon from Earth since the bodies are tidally locked. And its quite apparent from the images, that the moon’s far side looks completely different from the side facing Earth. The far side lacks the large, dark, basaltic plains, or maria, that are so prominent on the Earth-facing side.
“It is surprising how much brighter Earth is than the moon,” said Adam Szabo, DSCOVR project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, in a statement.
“Our planet is a truly brilliant object in dark space compared to the lunar surface.”
DSCOVR is a joint mission between NOAA, NASA, and the U.S Air Force (USAF) that is managed by NOAA. The satellite and science instruments were provided by NASA and NOAA.
Technician works on NASA Earth science instruments and Earth imaging EPIC camera (white circle) housed on NOAA/NASA Deep Space Climate Observatory (DSCOVR) inside NASA Goddard Space Flight Center clean room in November 2014. Credit: Ken Kremer/kenkremer.com
DSCOVR was first proposed in 1998 by then US Vice President Al Gore as the low cost ‘Triana’ satellite to take near continuous views of the Earth’s entire globe to feed to the internet as a means of motivating students to study math and science. It was eventually built as a much more capable Earth science satellite that would also conduct the space weather observations.
But Triana was shelved for purely partisan political reasons and the satellite was placed into storage at NASA Goddard and the science was lost until now.
It was also dubbed “Goresat.’
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
Video caption: This animation shows images of the far side of the moon, illuminated by the sun, as it crosses between the DISCOVR spacecraft’s Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth – one million miles away. Credit: NASA/NOAA
NOAA/NASA Deep Space Climate Observatory (DSCOVR) undergoes processing in NASA Goddard Space Flight Center clean room. Solar wind instruments at right. DSCOVER launched in February 2015 atop SpaceX Falcon 9 rocket. Credit: Ken Kremer/kenkremer.com
Launch of NOAA DSCOVR satellite from Cape Canaveral Air Force Station on Feb. 11, 2015 to monitor solar storms and space weather. Credit: Julian Leek
NOAA's DSCOVR satellite launches from Cape Canaveral Air Force Station on Feb. 11, 2015. DSCOVR will provide NOAA space weather forecasters more reliable measurements of solar wind conditions, improving their ability to monitor potentially harmful solar activity. Credit: Alan Walters/AmericaSpace
After a 17 year long wait, a new American mission to monitor intense solar storms and warn of impeding space weather disruptions to vital power grids, telecommunications satellites and public infrastructure was launched atop a SpaceXFalcon 9 on Wednesday, Feb. 11, from Cape Canaveral, Florida, to start a million mile journey to its deep space observation post.
The third time proved to be the charm when the Deep Space Climate Observatory, or DSCOVR science satellite lifted off at 6:03 p.m. EST Wednesday from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida.
The spectacular sunset blastoff came after two scrubs this week forced by a technical problem with the Air Force tracking radar and adverse weather on Sunday and Tuesday.
The $340 million DSCOVR has a critical mission to monitor the solar wind and aid very important forecasts of space weather at Earth at an observation point nearly a million miles from Earth. It will also take full disk color images of the sunlit side of Earth at least six times per day that will be publicly available and “wow” viewers.
Launch of NOAA DSCOVR satellite from Cape Canaveral Air Force Station on Feb. 11, 2015 to monitor solar storms and space weather. Credit: Julian Leek
The couch sized probe was targeted to the L1 Lagrange Point, a neutral gravity point that lies on the direct line between Earth and the sun located 1.5 million kilometers (932,000 miles) sunward from Earth. At L1 the gravity between the sun and Earth is perfectly balanced and the satellite will orbit about that spot just like a planet.
L1 is a perfect place for the science because it lies outside Earth’s magnetic environment. The probe will measure the constant stream of solar wind particles from the sun as they pass by.
The DSCOVR spacecraft (3-axis stabilized, 570 kg) will be delivered to the Sun-Earth L1 point, 1.5 million km (1 million miles) from the Earth, directly in front of the Sun. A Halo (Lissajous) orbit will stabilize the craft’s position around the L1 point while keeping it outside the radio noise emanating from the Sun. (Illustratin Credit: NASA)
DSCOVR is a joint mission between NOAA, NASA, and the U.S Air Force (USAF) that will be managed by NOAA. The satellite and science instruments are provided by NASA and NOAA. The rocket was funded by the USAF.
The mission is vital because its solar wind observations are crucial to maintaining accurate space weather forecasts to protect US infrastructure such as power grids, aviation, planes in flight, all types of Earth orbiting satellites for civilian and military needs, telecommunications, ISS astronauts and GPS systems.
It will take about 150 days to reach the L1 point and complete satellite and instrument checkouts.
DSCOVR will then become the first operational space weather mission to deep space and function as America’s primary warning system for solar magnetic storms.
It will replace NASA’s aging Advanced Composition Explorer (ACE) satellite which is nearly 20 years old and far beyond its original design lifetime.
“DSCOVR is the latest example of how NASA and NOAA work together to leverage the vantage point of space to both understand the science of space weather and provide direct practical benefits to us here on Earth,” said John Grunsfeld, associate administrator of NASA’s Science Mission Directorate in Washington.
DSCOVR was first proposed in 1998 by then US Vice President Al Gore as the low cost ‘Triana’ satellite to take near continuous views of the Earth’s entire globe to feed to the internet as a means of motivating students to study math and science. It was eventually built as a much more capable Earth science satellite that would also conduct the space weather observations.
But Triana was shelved for purely partisan political reasons and the satellite was placed into storage at NASA Goddard and the science was lost until now.
DSCOVR mission logo. Credit: NOAA/NASA/U.S. Air Force
DSCOVR is equipped with a suite of four continuously operating solar science and Earth science instruments from NASA and NOAA.
It will make simultaneous scientific observations of the solar wind and the entire sunlit side of Earth.
The 750-kilogram (1250 pound) DSCOVR probe measures 54 inches by 72 inches.
Technician works on NASA Earth science instruments and Earth imaging EPIC camera (white circle) housed on NOAA/NASA Deep Space Climate Observatory (DSCOVR) inside NASA Goddard Space Flight Center clean room in November 2014. Credit: Ken Kremer/kenkremer.com/AmericaSpace
The two Earth science instruments from NASA are the Earth Polychromatic Imaging Camera (EPIC) and the National Institute of Standards and Technology Advanced Radiometer (NISTAR).
EPIC will provide true color spectral images of the entire sunlit face of Earth at least six times per day, as viewed from an orbit around L1. They will be publically available within 24 hours via NASA Langley.
It will view the full disk of the entire sunlit Earth from sunrise to sunset and collect a variety of science measurements including on ozone, aerosols, dust and volcanic ash, vegetation properties, cloud heights and more.
Listen to my post launch interview with the BBC about DSCOVR and ESA’s successful IXV launch on Feb. 11.
NOAA/NASA Deep Space Climate Observatory (DSCOVR) undergoes processing in NASA Goddard Space Flight Center clean room. Solar wind instruments at right. DSCOVER will launch in February 2015 atop SpaceX Falcon 9 rocket. Credit: Ken Kremer/kenkremer.com/AmericaSpace
Launch of NOAA DSCOVR satellite from Cape Canaveral Air Force Station on Feb. 11, 2015 to monitor solar storms and space weather. Credit: John Studwell
Prelaunch view of SpaceX rocket on Cape Canaveral launch pad taken from LC-39 at the Kennedy Space Center. Credit: Chuck Higgins
DSCOVR mission logo. Credit: NOAA/NASA/U.S. Air Force
The long awaited Deep Space Climate Observatory, or DSCOVR science satellite is slated to blast off atop a SpaceX Falcon 9 on Sunday, Feb. 8, from Cape Canaveral, Florida on a mission to monitor the solar wind and aid very important forecasts of space weather at Earth.
DSCOVR is a joint mission between NOAA, NASA, and the U.S Air Force (USAF) that will be managed by NOAA. The satellite and science instruments are provided by NASA and NOAA.
Update Feb 8: Hold, Hold, Hold !!! 6:10 PM 2/8/15 Terminal Count aborted at T Minus 2 min 26 sec due to a tracking issue. NO launch of Falcon 9 today. rocket being safed now. next launch opportunity is Monday. Still TBD.
The rocket is provided by the USAF. SpaceX will try to recover the first stage via a guided descent to a floating barge in the Atlantic Ocean.
The weather outlook is currently very promising with a greater than 90 percent chance of favorable weather at launch time shortly after sunset on Sunday which could make for a spectacular viewing opportunity for spectators surrounding the Florida Space coast.
Liftoff atop the SpaceX Falcon 9 rocket is targeted for at 6:10:12 p.m. EST on Feb. 8, from Cape Canaveral Air Force Station Space Launch Complex 40.
There is an instantaneous launch window, meaning that any launch delay due to weather, technical or other factors will force a scrub to Monday.
The launch will be broadcast live on NASA TV: http://www.nasa.gov/nasatv
NASA’s DSCOVR launch blog coverage of countdown and liftoff will begin at 3:30 p.m. Sunday.
NOAA/NASA Deep Space Climate Observatory (DSCOVR) undergoes processing in NASA Goddard Space Flight Center clean room. Solar wind instruments at right. DSCOVER will launch in February 2015 atop SpaceX Falcon 9 rocket. Credit: Ken Kremer/kenkremer.com/AmericaSpace
“DSCOVR is NOAA’s first operational space weather mission to deep space,” said Stephen Volz, assistant administrator of the NOAA Satellite and Information Service in Silver Spring, Maryland, at the pre-launch briefing today (Feb. 7) at the Kennedy Space Center in Florida.
The mission of DSCOVR is vital because its solar wind observations are crucial to maintaining accurate space weather forecasts to protect US infrastructure from disruption by approaching solar storms.
“DSCOVR will maintain the nation’s solar wind observations, which are critical to the accuracy and lead time of NOAA’s space weather alerts, forecasts, and warnings,” according to a NASA description.
“Space weather events like geomagnetic storms caused by changes in solar wind can affect public infrastructure systems, including power grids, telecommunications systems, and aircraft avionics.”
DSCOVR will replace NASA’s aging Advanced Composition Explorer (ACE) satellite which is nearly 20 years old and far beyond its original design lifetime.
The couch sized probe is being targeted to the L1 Lagrange Point, a neutral gravity point that lies on the direct line between Earth and the sun located 1.5 million kilometers (932,000 miles) sunward from Earth. At L1 the gravity between the sun and Earth is perfectly balanced and the satellite will orbit about that spot just like a planet.
L1 is a perfect place for the science because it lies outside Earth’s magnetic environment. The probe will measure the constant stream of solar wind particles from the sun as they pass by.
Diagram of the five Lagrange points associated with the sun-Earth system, showing DSCOVR orbiting the L-1 point. Image is not to scale. Credit: NASA/WMAP Science Team
This will enable forecasters to give a 15 to 60 minute warning of approaching geomagnetic storms that could damage valuable infrastructure.
DSCOVR is equipped with a suite of four continuously operating solar science and Earth science instruments from NASA and NOAA.
It will make simultaneous scientific observations of the solar wind and the entire sunlit side of Earth. Three instruments will help measure the solar wind on the DSCOVR mission: (shown from left to right), the Faraday cup to monitor the speed and direction of positively-charged solar wind particles, the electron spectrometer to monitor electrons, and a magnetometer to measure magnetic fields. Credit: NASA/DSCOVR
The 750-kilogram DSCOVR probe measures 54 inches by 72 inches.
I saw the DSCOVR spacecraft up close at NASA Goddard Space Flight Center in Maryland last fall during processing in the clean room.
NOAA/NASA/USAF Deep Space Climate Observatory (DSCOVR) undergoes processing in NASA Goddard Space Flight Center clean room. Probe will launch in February atop SpaceX Falcon 9 rocket. Credit: Ken Kremer – kenkremer.com
A secondary objective of the rocket launch for SpaceX is to conduct their second attempt to recover the Falcon 9 first stage booster on an ocean going barge. Read my articles about the first attempt in January 2015, starting here.
It was originally named ‘Triana’ (aka Goresat) and was conceived by then US Vice President Al Gore as a low cost satellite to take near continuous views of the Earth’s entire globe to feed to the internet as a means of motivating students to study math and science. It was eventually built as a much more capable Earth science satellite as well as to conduct the space weather observations.
But Triana was shelved for purely partisan political reasons and the satellite was placed into storage and the science was lost until now.
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
The team is ready for the launch of NASA’s DSCOVR spacecraft aboard a SpaceX Falcon 9 rocket. L/R Mike Curie KSC NASA News Chief, Stephen Volz, assistant administrator NOAA, Tom Berger, director of NOAA Space Weather Prediction Center Boulder Colorado,Steven Clark, NASA Joint Agency Satellite Division, Col. D. Jason Cothern, Space Demonstration Division chief at Kirkland AFB NM. Hans Koenigsmann, VP of mission assurance at SpaceX in Hawthorne, California, Mike McAlaneen, launch weather officer 45th Space wing Cape Canaveral Air Force Station, Florida. Credit: Julian Leek
