Dawn

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Dawn launched in 2007 on a journey that put about 4.3 billion miles (6.9 billion kilometers) on its odometer. Propelled by ion engines, the spacecraft achieved many firsts until its extended mission concluded on Nov. 1, 2018.

In 2011, when Dawn arrived at Vesta, the second largest world in the main asteroid belt, the spacecraft became the first to orbit a body in the region between Mars and Jupiter.

In 2015, when Dawn went into orbit around Ceres, a dwarf planet that is also the largest world in the asteroid belt, the mission became the first to visit a dwarf planet and go into orbit around two destinations beyond Earth.

Among its accomplishments, Dawn showed how important location was to the way objects in the early solar system formed and evolved. Dawn also reinforced the idea that dwarf planets could have hosted oceans over a significant part of their history – and potentially still do. The data Dawn beamed back to Earth from its four science experiments enabled scientists to compare two planet-like worlds that evolved very differently.

10 Things to Know About Dawn

10 Need-to-Know Things About Dawn

1

Two-for-One First

Dawn was the first spacecraft to orbit two extraterrestrial destinations (Vesta and Ceres).

2

And ... First Orbit

When Dawn arrived at Vesta, it became the first spacecraft to orbit an object in the main asteroid belt

3

And ... First Look

When Dawn arrived at Ceres, it was the first spacecraft to visit a dwarf planet

Full View of Vesta

4

Location, Location, Location

Dawn showed us that location was key to how the early system organized and evolved.

5

Ocean Worlds

Dawn reinforced that dwarf planets, not just icy moons, could have hosted oceans during a large part of their historyand potentially still do.

6

Building Blocks of Life

Dawn found organics at Ceres and left us wanting to know more.

7

Science Fiction to Fact

Star Wars’ far-ranging “TIE” fighters stand for “twin ion engine.” Thanks to its own ion engines, Dawn broke several exploration records.

8

More than a Space Rock

Dawn found Vesta was a more varied world than scientists expected.

9

Bright Spots

Dawn revealed that Ceres is geologically active—or was very recently.

10

Science to the End

Dawn gathered science data at Ceres and returned it to Earth right up to the point the spacecraft ran out of fuel.

Last Look at Ceres

11

Bright Spots

Dawn revealed that Ceres is geologically active—or was very recently.

Major Engineering Achievements

Major Engineering Achievements

  • First space mission to orbit two destinations
  • Record-breaking use of solar-electric propulsion: 25,700 mph, 2.7x any prior spacecraft and nearly equal to the velocity provided by Dawn’s Delta launch vehicle
  • Active powered flight: 5.9 years (54% of the time in space as of Sep. 7, 2018)

Key Mission Findings

Key Mission Findings

Dawn orbited Vesta for more than a year, from July 2011 to September 2012. Its investigation confirmed that Vesta is the parent of the HED (howardites, eucrites, and diogenites) meteorites, which Dawn connected to Vesta’s large south polar basin, a priceless cosmic connection between samples in hand and a singular event on a small planet.

Sheer walls of impact crater on asteroid.
The ejected material from this young crater in the Rheasilvia impact basin likely comes from deep inside Vesta. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA | › Full Image and Caption

Vesta is small enough (about the same size as Saturn's moon Enceladus) to have been deeply scarred by the Rheasilvia impact that launched the HEDs, but large enough to have differentiated into an iron core, silicate mantle, and igneous crust. Dawn also found hydrated and carbon rich material on its surface supplied by impactors, a result that was unexpected based on pre-Dawn telescopic observations.

After its escape from Vesta and its journey onward, Dawn entered orbit around Ceres in March 2015. Dawn discovered that the inner solar system’s only dwarf planet was an ocean world where water and ammonia reacted with silicate rocks. As the ocean froze, salts and other telltale minerals concentrated into deposits that are now exposed in many locations across the surface. Dawn also found organics in several locations on Ceres’ surface.

Key Mission Events

Key Mission Events

2007 — Launch (September)

2009 — Mars Gravity Assist (February)

2011 — Vesta Arrival (July)

2012 — Vesta Departure (September)

2015 — Ceres Arrival (March)

2016 — End of prime mission (June)

2016 — Start of first extension (July)

2017 — Start of second extension (November)

Go to Mission Timeline ›

Notable Explorers

Quick Facts

Quick Facts

Type: Orbiter

Status: Successful

Launch Date: Sept. 27, 2007 | 11:34 UTC

Launch Location: Cape Canaveral Air Force Station, Florida

Destinations: Vesta and Ceres

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Dawn: By the Numbers

Dawn By the Numbers

Graphic showing Dawn's impressive numbers logged during the mission.
Dawn's end of mission statistics. Credit: NASA/JPL-Caltech | › Full image and caption

Key statistics from the end of mission:

51,385 hours of ion engine thrusting.

172 GB of science data collected.

3,052 orbits around Vesta and Ceres

100,000 images taken.

4.3+ billion miles (6.9+ billion kilometers) traveled since launch.

367+ million miles (591+ million kilometers): Farthest distance from Earth.

Top Dawn Images

View a curated selection of Dawn's best images.

More to Explore

  • Spacecraft

    View image gallery of NASA's Dawn spacecraft.

  • Vesta

    View image gallery of the second-largest world in the asteroid belt.

  • Ceres

    View image gallery of the dwarf planet Ceres.

More Resources

More Resources

Dawn News