OPUS (Outer Planets Unified Search) is a web-based search tool that allows researchers and members of the public to find and download data from NASA missions to the outer planets (Jupiter, Saturn, Uranus, Neptune, and various bodies beyond such as Pluto and MU69/Ultima Thule). It also includes observations taken of those planets from the Hubble Space Telescope. OPUS is a product of the Ring-Moon Systems Node of NASA's Planetary Data System (PDS). In addition to the web interface, OPUS supports an API so that third-party software can perform searches and retrieve results.

For more information about OPUS, including which spacecraft and instruments are available, see About under the Help menu. For more information about which particular bundles/volumes are available in OPUS, see Bundles/Volumes under the Help menu. For more information about the third-party API, see API Guide under the Help menu.

We are proud to announce a new version of OPUS (called OPUS3) that was released in May, 2019, the 10th anniversary of OPUS. This version contains a more modern look-and-feel and a streamlined user interface that makes searching for, browsing, and downloading spacecraft observations simpler than ever.

For previous users of OPUS, the primary differences are:

The Browse Results Tab

• You may now quickly move through a large result set by using the slider marked "Observation #". The selected observation number will appear in the top-left corner of the thumbnail gallery or the top row of the metadata table.
• As before, you may click on a table header to sort by that metadata field or to toggle the sort order between ascending and descending. The selected sort is also shown using a series of "pills" in both the gallery and table views:
  
  • Observation Start Time
  • OPUS ID
  
  You may click on the icon to remove the metadata field from the sort (note that you must always have at least one sort field, and you must always have OPUS ID as a sort field to provide a unique sort order). You may also click on the or icons to toggle the sort order of that metadata field between ascending and descending.

The Hamburger Menu

• Each observation thumbnail, each row in the metadata table, and the observation detail dialog contain a "hamburger" menu (). This menu provides easy access to features such as adding or removing one more observations from the cart and downloading data or a metadata CSV file for a single observation.

The Cart

• The Selections tab has been renamed to Cart to better represent its function. But don't worry, downloading observations is still free!
• You may add observations to the cart by clicking on the shopping cart icon at the bottom of any thumbnail or at the bottom of the observation detail dialog. Once an observation is in the cart the icon changes to a trash can, which you may click on to remove the observation from the cart.
• On the Cart tab, you now have the ability to change the sort order of the displayed thumbnails or table rows.
• On the Cart tab, the available products include tooltips () that give details about each file type.

Selecting and Viewing Metadata

• choose columns has been renamed to Select Metadata. This menu item, which is available on both the Browse Results and Cart tabs, allows you to select which metadata you are interested in seeing in the table view, the observation detail dialog, the Detail tab, and any CSV files you may download.
• Clicking on any thumbnail will display the observation detail dialog. This dialog, which may be moved around your browser window, includes an enlarged version of the thumbnail and displays the values of the metadata you have selected. You may use the finger buttons at the bottom ( and ) or the keyboard arrow keys to navigate to other observations.

Please refer to Getting Started under the Help menu for complete information on how to use OPUS.

While we at the Ring-Moon Systems Node like to think that all scientific data is beautiful, we understand that you might be interested in more traditional images. You can follow these steps to retrieve some great ones:

1. OPUS contains a variety of data types, but you'll want to restrict your search to images. You can do this by clicking on Observation Type under General Constraints on the left side of the Search tab. Then select the Image checkbox.
2. If you are looking for images of a particular planet or moon, you can select it in the Intended Target Name search box. First click on the planet you are interested in and then you will be able to select checkboxes next to the particular bodies available. If you skip this step, you will simply get all images. Note that this won't give you every image containing the body you've selected, but it's a good start.
3. At this point you can click on the Browse Results tab and simply scroll through the thumbnails of the (hundreds of thousands of) available images. If you click on a thumbnail, you will see a larger image and have the ability to navigate using the right and left arrow keys or by clicking on the pointing fingers.
4. If you are really interested in only a single planet or moon, expand the Surface Geometry Constraints menu on the left and click on Surface Geometry Target Selector. Then select the body in the search box that appears. This will show you every image that contains that body from a subset of the missions and instruments that are supported. You will also now have the ability to narrow your search by using the search terms in the [Body] Surface Geometry Constraints menu. For example, you might want to experiment with Body Center Distance or Body Center Resolution to restrict your search to close-up images.

Some types of metadata vary for each pixel in an observation, or for the observation as a whole. For example, an image covers a particular swath of sky, and each pixel corresponds to a unique right ascension and declination. An observation of a planetary ring will cover a radial range and a longitude range. An observation of a body will have a range of incidence, emission, and phase angles. An entire observation will have a time range defined by an observation start time and an observation stop time. And a spectrometer or a filter on an imaging camera will have a wavelength range defined by the minimum wavelength and maximum wavelength available. To make these ranges easy to search, OPUS summarizes them for each observation by recording the minimum and maximum for any pixel in the image (or for the observation as a whole). We call this the "observation range". When performing your search, you can also select a minimum and a maximum value. We call this the "search range".

There are three ways you can compare these two ranges, representing the three fundamental ways two ranges can overlap:

1. ANY - The observation range overlaps at least some with the search range. In other words, the observation maximum is greater than or equal to the search minimum, and the observation minimum is less than or equal to the search maximum. This option is used to request the widest possible set of observations that contain at least some of the range you are searching for.
2. ALL - The observation range covers the search range. In other words, the observation minimum is less than or equal to the search minimum, and the observation maximum is greater than or equal to the search maximum. This option is used to ensure that an entire feature you are looking for (such as a crater) is visible in the observation.
3. ONLY - The observation range lies within the search range. In other words, the observation minimum is greater than or equal to the search minimum, and the observation maximum is less than or equal to the search maximum. This option is used to tightly constrain your search to the smallest possible set of results.

The are two basic methods to find observations containing a particular body.

Method 1

You may use the Intended Target Name field to search for all observations containing one or more specified bodies. This field only identifies one body per observation, the one selected by the original science planner to represent the purpose of the observation. In some cases, the body may not even be in the field of view (some observations of Saturn's rings have Saturn as the Intended Target Name). However, this method works with all missions and instruments.

Method 2

The surface geometry metadata, supplied by the Ring-Moon Systems Node, provides information about every body in the field of view, regardless of how large or small it is. By selecting a single Surface Geometry Target Selector under Surface Geometry Constraints you can limit your search to only observations containing the given body in the field of view. However, this feature is only available for Cassini ISS, UVIS, and VIMS, Galileo SSI, New Horizons LORRI, and Voyager ISS.

There are four ways that you can accomplish this goal. Note that methods 1 through 3 only work for instruments that support surface geometry (currently Cassini ISS, UVIS, and VIMS, Galileo SSI, New Horizons LORRI, and Voyager ISS).

Method 1

1. Under Surface Geometry Constraints select the Multiple Target List search field. The Multiple Target List field contains an alphabetical comma-separated list of all targets in the field of view for which surface geometry information is available.
2. If you want to find observations that have only two particular bodies and no others, select matches from the query type dropdown and enter "Body1,Body2" in the search field. Make sure the bodies are in alphabetical order (e.g. "Dione,Tethys" not "Tethys,Dione"). The result set will now contain only observations that have those two, and only those two, bodies in the field of view.
3. If you want to find observations that have two particular bodies in the field of view, but other bodies are OK too, we need to use a regular expression. Select regex in the query type dropdown and enter "Body1.*Body2" in the search field. Again make sure that "Body1" is alphabetically before "Body2".

Method 2

1. Restrict the search to whatever mission, instrument, time period, bundle/volume, etc. that you are interested in.
2. Under Surface Geometry Constraints select the Surface Geometry Target Selector search field. Select the first body in the Surface Geometry Target Selector search box.
3. Using entries under [Body] Surface Geometry Constraints, restrict your search using lighting geometry, distance, resolution, etc.
4. Select the Browse Results tab and then click on Download CSV to retrieve a CSV containing information about each observation of the first body.
5. Go back to the Search tab and select a different body under Surface Geometry Target Selector. Restrict this search as desired.
6. Select the Browse Results tab and then click on Download CSV to retrieve a CSV containing information about each observation of the second body.
7. Use your favorite comparison tool or text editor to look at the two CSV files to see which observations they have in common.

Method 3

1. Restrict the search to whatever mission, instrument, time period, bundle/volume, etc. that you are interested in.
2. Under Surface Geometry Constraints select the Surface Geometry Target Selector search field. Select the first body in the Surface Geometry Target Selector search box.
3. Using entries under [Body] Surface Geometry Constraints, restrict your search using lighting geometry, distance, resolution, etc.
4. Select the Browse Results tab and visually scan through the thumbnails looking for images with two or more bodies in them.
5. When you find such an image, click on the icon or select View Detail from the observation's menu. Scroll down the Detail page to see which bodies are present in the observation.

Method 4

Note: This method is only applicable to Cassini observations. In many cases, the Cassini team marked "mutual event" observations using the Cassini Observation Name.

1. Restrict the search to the Cassini mission or a particular Cassini instrument. You can also restrict your search by time period, bundle/volume, etc. at this time.
2. Select the Observation Name search field under Cassini Mission Constraints. Enter "MUTUALEVE" in the search box using the contains search type.

There are two methods to search for images that were taken using a particular color filter.

Method 1

This method relies on knowledge of the filters used by a particular imaging instrument (currently Cassini ISS, Galileo SSI, Voyager ISS, New Horizons LORRI, and the Hubble instruments). You must first select the instrument you are interested in (e.g. Cassini ISS) by using the Instrument Name search box. When you do this, a search menu with a name like Cassini ISS Constraints will become available. Under this menu there will be a search field called Filter or Filter Name. Selecting this field will allow you to select one or more filters to restrict your search.

Method 2

One of the benefits of OPUS is the ability to search across missions and instruments using common search fields. For all observations where it makes sense, OPUS provides wavelength information under the Wavelength Constraints menu. The Wavelength search field allows you to restrict your search based on the wavelengths avaible in the respective instrument, instrument mode, and filter combinations. For example, for an imaging instrument the wavelength range is based on the filter bandpass. For a spectroscopic instrument, the wavelength range is based on the limits of the spectrum collected. This field can thus be used to select all observations that include a particular wavelength range, and you can use this to restrict your search to observations of a specific color. For example, you might look for "red" observations by searching for a wavelength range of 600-700 nm.

Please see the FAQ titled "What do Any, All, and Only Mean?" to understand how you can further control your search.

A "movie" is a series of observations that was taken in rapid succession while an instrument was pointing at approximately the same point in space or while tracking a particular body or feature. Movies were most commonly taken by Cassini. In many, but not all, cases, movies were marked by the Cassini team with an Observation Name that contains "MOV" or "MOVIE". To search for these, select the Cassini mission or a particular Cassini instrument and then select the Observation Name search field under Cassini Mission Constraints. Enter "MOV" in the search box using the contains search type. In the special case of movies of Saturn's F ring, you can use "FMOV" instead.

A future version of OPUS will automatically detect observation series that appear to be movies or mosaics and provide a specific means to search for them.

Thumbnails of imaging instruments (e.g. Cassini ISS, Galileo SSI, Voyager ISS, New Horizons LORRI, and most Hubble instruments) have a variety of filters that can be used. We color the thumbnails on the Browse Results page in an attempt to convey the approximate color of the filter that was used. If a thumbnail is not colored, it usually means a clear filter was used.