1 min read
Mars Oppositions 2016 and 2018
Mars Seen in Clear and Dusty Conditions
These side-by-side images of Mars, taken roughly two years apart, show very different views of the same hemisphere of Mars. Both were captured when Mars was near opposition, which occurs about every two years, when Earth’s orbit catches up to Mars’ orbit. At that time, the Sun, Earth, and Mars fall in a straight line, with Mars and the Sun on “opposing” sides of Earth.
The image on the left, taken on May 12, 2016, shows a clear atmosphere. The picture on the right, taken on July 18, 2018, features a global dust storm, with spring in the southern hemisphere.
Scientists believe that heat from the southern hemisphere’s spring and summer triggers dust storms that originate in the Hellas Basin, the lowest point on the planet.
Although the Red Planet is showing virtually the same face to us, classical dark features first mapped by early sky watchers look different in each image. This is partly because of obscuration from the 2018 global dust storm, but also because the northern hemisphere was tilted toward Earth in 2016, and away from Earth in 2018. The latter view reveals more of southern hemisphere, including the cloud-enshrouded south polar region.
The phenomenon of opposition is a result of the difference in orbital periods between Earth’s orbit and Mars’ orbit. While Earth takes the familiar 365 days to travel once around the Sun, Mars takes 687 Earth days to make its trip around our star. As a result, Earth makes almost two full orbits in the time it takes Mars to make just one, resulting in the occurrence of Martian oppositions about every 26 months.
About the Data
- Data DescriptionData DescriptionProposal: A description of the observations, their scientific justification, and the links to the data available in the science archive.
Science Team: The astronomers who planned the observations and analyzed the data. "PI" refers to the Principal Investigator.The HST observations include those from program 15456 (M. Mutchler) - InstrumentInstrumentThe science instrument used to produce the data.WFC3/UVIS
- Exposure DatesExposure DatesThe date(s) that the telescope made its observations and the total exposure time.July 18, 2018
- FiltersFiltersThe camera filters that were used in the science observations.F275W, F410M, F502N, F673N
- Object NameObject NameA name or catalog number that astronomers use to identify an astronomical object.Mars
- Object DescriptionObject DescriptionThe type of astronomical object.Planet
- Release DateJuly 26, 2018
- Science ReleaseSaturn and Mars Team Up to Make Their Closest Approaches to Earth in 2018
- Credits
This image is a composite of separate exposures acquired by the WFC3/UVIS instrument. Several filters were used to sample various wavelengths. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are: Purple: F275W Blue: F410M Green: F502N Red: F673N
Related Images & Videos
Saturn and Mars at Opposition
Hubble’s Latest Portraits of Saturn and Mars NASA’s Hubble Space Telescope has photographed Saturn, left, and Mars, right, near their closest approaches to Earth in June and July 2018. The planets were photographed near opposition, when the Sun, Earth and an outer planet are...
Saturn Opposition 2018
Hubble Takes Portrait of Opulent Ring World Saturn is by far the solar system’s most photogenic planet, and in this latest Hubble Space Telescope snapshot it is especially so because Saturn’s magnificent ring system is near its maximum tilt toward Earth (which was in 2017)....
Saturn and Six of Its Moons (Annotated)
This annotated time-lapse animation of Hubble observations shows the rotation of Saturn and six of its moons over roughly 20 hours. In a textbook demonstration of Keplerian motion, the moons closer to the planet orbit more rapidly, while those farther away move more slowly. This...
Mars and Its Moons (Annotated)
This time-lapse animation of Hubble images shows Mars rotating over 43 minutes. The video begins with the moon Deimos traveling from right to left as it orbits Mars. Then Phobos makes an appearance from the right before disappearing behind the Red Planet’s shadow. The...
Mars at Opposition (2016 and 2018)
This video shows the difference in orientation of Mars between the 2016 and 2018 observations, and it also illustrates the obscuration by the 2018 dust storm. The opening image, taken by the Hubble Space Telescope on May 12, 2016, shows a clear atmosphere. Three-dimensional...
Share
Details
Claire Andreoli
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
claire.andreoli@nasa.gov
