Karl G. Jansky Very Large Array (VLA)

Plains of San Augustin, west of Socorro, New Mexico

 
Atacama Millimeter/submillimeter Array (ALMA)
Atacama Desert, Chile

RADIO OBSERVATIONS

All planets emit thermal (blackbody) radiation, which can be imaged at radio wavelengths.

Some bodies emit nonthermal emissions, such as synchrotron radiation from Jupiter highlightes below.

Molecular emission and absorption bands have been observed from a variety of bodies.

Below we highlight results on the 4 giant planets, their rings, and satellites, as well as comets.

A review of radio observations of the giant planets is give in: de Pater, I, Molter, E.M., Moeckel, C.M., 2023. A Review of Radio Observations of the Giant Planets: Probing the Composition, Structure and Dynamics of their Deep Atmospheres. Remote Sensing, Vol. 15, 1313, pp49. https://doi.org/10.3390/rs15051313

Jupiter

From Jupiter we receive both thermal and nonthermal emissions.

First ALMA Millimeter-wavelength Maps of Jupiter,with a Multi-Wavelength Study of Convection. (click to enlarge image and get more information about this research). (CREDITS: Imke de Pater (UC Berkeley), Robert J. Sault (Univ. Melbourne))

Peering through Jupiter's clouds:A radio image of Jupiter from the VLA at three wavelengths: 2 cm in blue, 3 cm in gold, and 6 cm in red (click to enlarge image and see radio maps of the planet). A uniform disk has been subtracted to better show the fine banded structure on the planet. The pink glow surrounding the planet is synchrotron radiation produced by spiraling electrons trapped in Jupiter's magnetic field. Banded details on the planet's disk probe depths of 30-90 km below the clouds. This image is averaged from 10 hours of VLA data, so any longitudinal structure is smeared by the planet's rotation. (CREDITS: Imke de Pater, Michael H. Wong (UC Berkeley), Robert J. Sault (Univ. Melbourne))

Radio images of Jupiter:This 4-panel photograph (click to enlarge image) shows longitude-smeared images of Jupiter at wavelengths of 2, 3.5 and 6 cm; the latter image shows the total emission (thermal + nonthermal), as well as an image where the nonthermal (synchrotron) radiation was subtracted. These images were taken close in time with the Galileo probe entry into Jupiter's atmosphere, Dec. 7, 1995. (Ref: de Pater, I., D. Dunn, K. Zahnle and P.N. Romani, 2001. Comparison of Galileo Probe Data with Ground-based Radio Measurements. Icarus, vol. 149, 66-78.

First longitude-resolved radiomap of Jupiter:The image at left is a radio image of Jupiter at 2cm, derived from VLA observations taken on 25 January 1996. The data were taken by Imke de Pater (UC Berkeley), and were further reduced and imaged by Chermelle Engel (University of Melbourne) and Bob Sault (ATNF). (Sault, R.J., C. Engel, and I. de Pater, 2002. Topographic imaging of Jupiter at radio wavelengths. Icarus, submitted.)

Impact of comet D/Shoemaker-Levy 9 with Jupiter:SL9 (6 panel image) The impact of comet Shoemaker-Levy 9 with Jupiter in July 1994 drastically changed the radiation characteristics of Jupiter's synchrotron radiation. The observations can largely be explained using a model of enhanced radial diffusion of the radiating electrons, as well as a direct acceleration of the electrons by the upward propagating shock. This image shows data (panels a and b) and models (panels c-f). For details see Brecht, S.H., I. de Pater, D.J. Larson, and M.E. Pesses, 2000. Modification of the Jovian radiation Belts by Shoemaker-Levy 9: An Explanation of the Data. Icarus, vol. 151, 25-38.

Jupiter's synchrotron radiation:Energetic electrons trapped in Jupiter's magnetic field emit synchrotron radiation. The image at left (click to enlarge image) is a false-color image of this emission, at a Jovian longitude of 312 degrees. The data were obtained with the Very Large Array at a wavelength of 20 cm. We overplotted magnetic field lines at an equatorial `distance' of 1.5 and 2.5 Jovian radii (from Jupiter's center) (from Jack Connerney's O6 magnetic model). (Ref: de Pater, I., M. Schulz, and S.H. Brecht, 1997. Synchrotron evidence for Amalthea's influence on Jupiter's electron radiation belt. J. Geoph. Res., vol. 102, pp. 22,043 - 22,064)

Three-dimensional tomographic reconstruction of Jupiter's nonthermal radio emissivity. We used R.J. Sault's 3D Fast Fourier Transform algorithm on the VLA data shown at left, and R. E. Gooch's visualization software package for displaying and making movies (click to view enlarged image plus movie). (Ref: de Pater and Sault, 1998. An intercomparison of 3-D reconstruction techniques using data and models of Jupiter's synchrotron radiation. J. Geophys. Res. vol. 103, pp. 19,973-19,984)

Io

From Io we receive thermal emission from its (sub)surface and atmosphere.

A composite image of Io, in front of a Cassini photo of Jupiter. The observations for the first time show plumes of sulfur dioxide (yellow) rising up from Io's volcanoes. (click to enlarge image and get more information about this research). (CREDITS: Imke de Pater (UC Berkeley); ALMA; S. Dagnello/NRAO; NASA/ESA)

Saturn

We receive thermal radiation from Saturn itself and its rings; the latter emission is dominated by Saturn's thermal emission reflected off the rings.

VLA Observations reveal the effect of mega-storms in Saturn's atmosphere. More images and information are shown when clicking on the icon.

Saturn observed at a wavelength of 2 cm with the upgraded VLA in 2015. More images and information are shown when clicking on the icon. Figure from: Zhang, Z., Hayes, A. G., de Pater, I., Dunn, D. E., Janssen, M. A., Nicholson, P. D., Cuzzi, J. N., Butler, B., Sault, R.J., Chatterjee, S., 2019. VLA multi-wavelength microwave observations of Saturn's C and B rings. Icarus, 317, 518-548.

Saturn observed at a wavelength of 2 cm with the VLA in Sep. 1994. Note the brighter (hotter) bands on Saturn, similar in appearance to Jupiter's banded structure. Saturn's main rings are easily distinguished too. More images are shown when clicking on the icon.

Uranus

We receive thermal radiation from Uranus itself, and recent ALMA images revealed thermal radiation also from its rings.

ALMA detects thermal radiation from Uranus' rings. Click the icon for more information.

Radio image of Uranus with the VLA, after the VLA upgrade. Click the icon for more information.

Radio spectrum of Uranus to show the sensitivity to different sources of opacity. Click the icon for more information.

Neptune

We receive thermal radiation from Neptune's atmosphere.

Radio image of Neptune with the ALMA at mm wavelengths. Click the icon for more information on ALMA observations of Neptune.

Radio image of Neptune with the VLA, after the VLA upgrade. Click the icon for more information on Neptune's radio spectrum, images and global circulation model.

Comets

Comet overview...

Our group is involved in imaging OH (maser) emission from comets using the VLA, and the thermal emission from molecules such as HCN, CS and the H2CO-ion with BIMA. Examples are shown of an OH image from comet Halley (taken with the VLA in Nov. 1985)[upper thumbnail], and an HCN spectrum [middle thumbnail] and dust emission image [lower thumbnail] from comet Hale-Bopp (taken in March 1997 with BIMA).

(Refs: de Pater, I., P. Palmer, and L.E. Snyder, 1986, the brightness distribution of OH around comet Halley, Astrophys. J. Lett., vol. 304, pp. L33-L36. de Pater, I., J.R. Forster, M. Wright, B. J. Butler, P. Palmer, J. M. Veal, M. F. A'Hearn, and L. E. Snyder, 1998, BIMA and VLA observations of Comet Hale-Bopp at 22 -- 115 GHz, Astron. J., vol. 116, pp. 987-996. Wright, M.C.H., I. de Pater, J. R. Forster, P. Palmer, L.E. Snyder, J.M. Veal M.F. A'Hearn, L.M. Woodney, W.M. Jackson, Y.-J. Kuan, and A.J. Lovell, 1998. Mosaiced Images and Spectra of J=1-->0 HCN and HCO+ emission from Comet Hale-Bopp (1995 O1). Astron. J., vol. 116, pp. 3018-3028.)

 

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