From Earthrise to the black hole: astronomy’s most famous images.
Photographs from history that capture humanity’s exploration of the heavens.
20 July 1969
One of the most iconic views of Earth, taken from the Apollo 11 spacecraft as it orbited the moon. Describing the scene, the astronaut Neil Armstrong said: ‘It suddenly struck me that that tiny pea, pretty and blue, was the Earth. I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didn’t feel like a giant. I felt very, very small’ | This caption was updated on 11 April 2019 to correct the date the picture was taken, photograph: Nasa.
21 July 1969
Buzz Aldrin, the lunar module pilot for the first moon landing, poses on the lunar surface. The footprints of the astronauts are clearly visible in the soil. Neil Armstrong took the picture with a 70mm Hasselblad lunar surface camera Photograph: American Photo Archive/Alamy
25 February 1979
This dramatic view of Jupiter’s great red spot and its surroundings was obtained by the Voyager 1 space probe
Photograph: JPL/Nasa/UIG/Getty Images
14 February 1990
Often referred to as ‘the pale blue dot’ image, this picture was taken when Voyager 1 was 4bn miles (6.4bn km) from Earth and 32 degrees above the ecliptic plane. Earth is a mere point of light, just 0.12 pixels in size when viewed from that distance. The fuzzy light is scattered sunlight because Earth was close to the sun (from the perspective of Voyager)
6 January 2004
The first colour image of Mars taken by the panoramic camera on the Mars Exploration Rover Spirit. It was the sharpest photograph ever taken on the surface of the planet
25 September 2012
Called the eXtreme Deep Field, or XDF, this photo was assembled by combining 10 years of Hubble space telescope photographs taken of a patch of sky at the centre of the original Hubble Ultra Deep Field. By collecting faint light over many hours of observation, the telescope revealed thousands of galaxies, both nearby and very distant, making it the deepest image of the universe ever taken at that time
Photograph: Hubble space telescope/Nasa/ESA
24 July 2015
A combination of images captured by the New Horizons space probe, with enhanced colours to show differences in the composition and texture of Pluto’s surface
10 April 2019
The first image of a black hole, captured by the Event Horizon telescope (EHT) – a planet-scale array of eight ground-based radio telescopes forged through international collaboration. The shadow of a black hole seen here is the closest we can come to an image of the black hole itself, a completely dark object from which light cannot escape
Black Hole Image Makes History; NASA Telescopes Coordinated Observations
A black hole and its shadow have been captured in an image for the first time, a historic feat by an international network of radio telescopes called the Event Horizon Telescope (EHT). EHT is an international collaboration whose support in the U.S. includes the National Science Foundation.
A black hole is an extremely dense object from which no light can escape. Anything that comes within a black hole’s “event horizon,” its point of no return, will be consumed, never to re-emerge, because of the black hole’s unimaginably strong gravity. By its very nature, a black hole cannot be seen, but the hot disk of material that encircles it shines bright. Against a bright backdrop, such as this disk, a black hole appears to cast a shadow.
The stunning new image shows the shadow of the supermassive black hole in the center of Messier 87 (M87), an elliptical galaxy some 55 million light-years from Earth. This black hole is 6.5 billion times the mass of the Sun. Catching its shadow involved eight ground-based radio telescopes around the globe, operating together as if they were one telescope the size of our entire planet.
“This is an amazing accomplishment by the EHT team,” said Paul Hertz, director of the astrophysics division at NASA Headquarters in Washington. “Years ago, we thought we would have to build a very large space telescope to image a black hole. By getting radio telescopes around the world to work in concert like one instrument, the EHT team achieved this, decades ahead of time.”
To complement the EHT findings, several NASA spacecraft were part of a large effort, coordinated by the EHT’s Multiwavelength Working Group, to observe the black hole using different wavelengths of light. As part of this effort, NASA’s Chandra X-ray Observatory, Nuclear Spectroscopic Telescope Array (NuSTAR) and Neil Gehrels SwiftObservatory space telescope missions, all attuned to different varieties of X-ray light, turned their gaze to the M87 black hole around the same time as the Event Horizon Telescope in April 2017. If EHT observed changes in the structure of the black hole’s environment, data from these missions and other telescopes could be used to help figure out what was going on.
While NASA observations did not directly trace out the historic image, astronomers used data from NASA’s Chandra and NuSTAR satellites to measure the X-ray brightness of M87’s jet. Scientists used this information to compare their models of the jet and disk around the black hole with the EHT observations. Other insights may come as researchers continue to pore over these data.
There are many remaining questions about black holes that the coordinated NASA observations may help answer. Mysteries linger about why particles get such a huge energy boost around black holes, forming dramatic jets that surge away from the poles of black holes at nearly the speed of light. When material falls into the black hole, where does the energy go?
“X-rays help us connect what’s happening to the particles near the event horizon with what we can measure with our telescopes,” said Joey Neilsen, an astronomer at Villanova University in Pennsylvania, who led the Chandra and NuSTAR analysis on behalf of the EHT’s Multiwavelength Working Group.
NASA space telescopes have previously studied a jet extending more than 1,000 light-years away from the center of M87. The jet is made of particles traveling near the speed of light, shooting out at high energies from close to the event horizon. The EHT was designed in part to study the origin of this jet and others like it. A blob of matter in the jet called HST-1, discovered by Hubble astronomers in 1999, has undergone a mysterious cycle of brightening and dimming.
Chandra, NuSTAR and Swift, as well as NASA’s Neutron star Interior Composition Explorer (NICER) experiment on the International Space Station, also looked at the black hole at the center of our own Milky Way galaxy, called Sagittarius A*, in coordination with EHT.
Getting so many different telescopes on the ground and in space to all look toward the same celestial object is a huge undertaking in and of itself, scientists emphasize.
“Scheduling all of these coordinated observations was a really hard problem for both the EHT and the Chandra and NuSTAR mission planners,” Neilsen said. “They did really incredible work to get us the data that we have, and we’re exceedingly grateful.”
Neilsen and colleagues who were part of the coordinated observations will be working on dissecting the entire spectrum of light coming from the M87 black hole, all the way from low-energy radio waves to high-energy gamma rays. With so much data from EHT and other telescopes, scientists may have years of discoveries ahead.
Let’s do something together. Dedicate some time today to do absolutely nothing besides trying to love the environment around you. We live in such a fast-paced world that slowing down can help us realize that there is no rush, there is no hurry, there is no fear, and that the world is as beautiful as we see it.
If we were able to look at a black hole from different orientations we would be able to see light even from parts of the accretion disc behind the black hole as they are lensed above and below the shadow region! [Credits: L. R. Weih & L. Rezzolla of Goethe University, Frankfurt]