A NASA Discovery mission to conduct the first orbital study
of the innermost planet
NASA logo carnegie institution logo JHU APL logo

Why Mercury?
The Mission
Gallery
Education
News Center
Science Operations
Who We Are
FAQs
Related Links
Contacts
Home


Download iPhone/iPad app Information about Mercury Flybys Question and Answer Mercury Orbit Insertion Where is MESSENGER? Where is Mercury now? Subscribe to MESSENGER eNews


Where Is MESSENGER?

The computer-generated images below are simulated views. The images were created using the Satellite Tool Kit (STK) software, which was developed by Analytical Graphics, Inc. Click on an image below to be directed to a descriptive caption and a larger, current view of the image.

Beginning with Mercury orbit insertion on March 18, 2011, the design of "Where Is MESSENGER?" was updated to reflect the changing nature of the MESSENGER mission. Just as the spacecraft orbit transitioned from an orbiter of the Sun to an orbiter of Mercury, the focus of this feature's views changed from primarily Sun centered to Mercury centered.


View from MESSENGER to Mercury

This image shows the surface of Mercury as seen from MESSENGER’s current position as well as the MESSENGER spacecraft’s current orbit and orientation.  Positions of stars with magnitude 5 or brighter are shown.



View of MESSENGER's Ground Track: 10.5° Field of View

The 10.5° field of view shows Mercury’s surface from MESSENGER looking directly beneath the spacecraft to the sub-spacecraft point. This perspective of Mercury reveals what the MESSENGER Wide-Angle Camera (WAC) would see if the WAC were pointed in this direction. The surface shown is from a global base map mosaic created from MESSENGER images. At lower altitudes, this view of the global base map may appear blurry, indicating that MESSENGER's current position enables WAC images to be acquired at a higher resolution than that of the global base map.




View of MESSENGER's Ground Track: 1.5° Field of View

The 1.5° field of view shows Mercury’s surface from MESSENGER looking directly beneath the spacecraft to the sub-spacecraft point. This perspective of Mercury reveals what the MESSENGER Narrow-Angle Camera (NAC) would see if the NAC were pointed in this direction. The surface shown is from a global base map mosaic created from MESSENGER images. At lower altitudes, this view of the global base map may appear blurry, indicating that MESSENGER's current position enables NAC images to be acquired at a higher resolution than that of the global base map.




View from the Earth

This image shows MESSENGER's location in its current orbit (in blue) as seen from the direction of Earth. Positions of stars with magnitude 5 or brighter are shown. During seasons when a segment of the orbit is behind the planet in this view, the radio signal between Earth and MESSENGER is occulted by Mercury, temporarily blocking communications. Information on Mercury's shape is obtained by recording the precise times of signal loss and reacquisition during those seasons.



View from the Sun

This image shows MESSENGER's location in its current orbit (in blue) as seen from the direction of the Sun. Positions of stars with magnitude 5 or brighter are shown. During "solar eclipse" seasons when a segment of the orbit is behind the planet in this view, MESSENGER and its solar array panels are in Mercury’s shadow, so MESSENGER's battery must power the spacecraft instruments and subsystems. The battery is then recharged each orbit after the solar array panels are again in sunlight.



Full View of Spacecraft Orbit

This image shows MESSENGER's location in its current orbit as seen from a viewpoint that provides visibility of 100% of the orbit at all times. Positions of stars with magnitude 5 or brighter are shown.



View from Above Mercury’s North Pole

This image shows MESSENGER's location in its current orbit (in blue) as seen from above Mercury’s north pole. Positions of stars with magnitude 5 or brighter are shown. During "dawn-dusk" seasons when the plane of the orbit is nearly aligned with the terminator (the line between day and night), thermal conditions on the spacecraft are the most benign, with relatively constant conditions during each orbit. Conversely, the more thermally challenging "noon-midnight" orbits occur when the plane of the orbit is nearly perpendicular to the terminator. The largest swings in temperature are experienced when the spacecraft transitions between the central nightside and overhead Sun at low elevations over the dayside surface.




Planet Positions around the Sun

This image shows the orbits and current positions of Mercury, Venus, and Earth. Positions of stars with magnitude 5 or brighter are shown from this perspective that is above the Sun and north of Mercury's orbit plane. Communication rates between MESSENGER and Earth increase when the planets approach each other, and the rates decrease as the distance between the planets increases. Superior solar conjunctions occur when Mercury is on the far side of the Sun from Earth. Communications can be disrupted for several days surrounding superior solar conjunction, depending on how fast Mercury is moving across the sky at the time. Mercury takes 88 Earth days to complete one orbit around the Sun.



View of MESSENGER’s Ground Track

This 2-D image shows the orbit ground track and MESSENGER's location above the Mercury surface. 

   Top  | Contacts
© 1999-2014 by JHU/APL