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Cloudy vs. Clear Atmospheres on Exoplanets WASP-67 b and HAT-P-38 b
This diagram compares Hubble Space Telescope observations of two "hot Jupiter"-class planets orbiting very closely to different sunlike stars. Astronomers measured how light from each parent star is filtered through each planet's atmosphere. Hubble near-infrared observations were used to measure the spectral fingerprint caused by the presence of water vapor in the atmosphere. HAT-P-38 b did have a water signature indicated by the absorption-feature peak in the spectrum. This is interpreted as indicating the upper atmosphere is free of clouds or hazes. By contrast, a very similar hot Jupiter, WASP-67 b, has a flat spectrum that lacks any water-absorption feature. This suggests that most of the planet's atmosphere is masked by high-altitude clouds.
About the Object
- R.A. PositionR.A. PositionRight ascension – analogous to longitude – is one component of an object's position.HAT-P-38 b: 02h 21m 31.9s; WASP-67b: 19h 42m 59.0s
- Dec. PositionDec. PositionDeclination – analogous to latitude – is one component of an object's position.HAT-P-38 b: +32° 14' 46"; WASP-67 b: -19° 56' 58"
- DistanceDistanceThe physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs.HAT-P-38 b: 812 light-years (249 parsecs); WASP-67 b: 734 light-years (225 parsecs)
- DimensionsDimensionsThe physical size of the object or the apparent angle it subtends on the sky.HAT-P-38 b is is 0.825 times Jupiter's diameter. WASP-67 b is 2.8 times Jupiter's diameter
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 data used in the HAT-P-38 b and WASP-67 b studies were from proposal 14260, P.I. Drake Deming (University of Maryland). - InstrumentInstrumentThe science instrument used to produce the data.HST>WFC3/IR
- Exposure DatesExposure DatesThe date(s) that the telescope made its observations and the total exposure time.HAT-P-38 b: Mar. 2, 2016 - Aug. 26, 2016; WASP-67 b: Oct. 22, 2016
- FiltersFiltersThe camera filters that were used in the science observations.HAT-P-38 b: WFC3/IR G141 (red grism), 282 minutes WASP-67 b: WFC3/IR G141 (red grism), 108 minutes
- Object NameObject NameA name or catalog number that astronomers use to identify an astronomical object.HAT-P-38 b WASP-67 b
- Object DescriptionObject DescriptionThe type of astronomical object.Extrasolar planet
- Release DateJune 5, 2017
- Science ReleaseHubble’s Tale of Two Exoplanets: Nature vs. Nurture
- Credit
Related Images & Videos
Cloudy vs. Clear Atmospheres on Two Exoplanets
This illustration compares the atmospheres of two "hot Jupiter"-class planets orbiting very closely to different sunlike stars. The planets are too far away for the Hubble Space Telescope to resolve any details. Instead, astronomers measured how the light from the parent stars...
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Last Updated
Mar 28, 2025
Contact
Media
Claire Andreoli
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
claire.andreoli@nasa.gov
Artwork Credit
NASA, ESA, Zena Levy (STScI)
Science Credit
NASA, ESA, Giovanni Bruno (STScI)
