2026 MAY 11

In this month’s issue:

1. A new home for the Newsletter

2. Jira Helpdesk

3. Comet processing

4. How to access MPC data

5. MPC User Group Meeting

1. The MPC Newsletter has a new home

Since February 2023, the MPC has published a monthly newsletter to share recent developments with users, solicit feedback from the community, and make our processes as transparent as possible. Until recently, the MPC Newsletter was published directly on the MPC website.

As you can see, the MPC Newsletter has now moved to a new home: Buttondown, a platform designed for email and newsletters.

This move was motivated by the growing popularity of the newsletter as a way to share MPC-related content, and by the need for a better subscription mechanism to reach a broader community.

Until now, distributing the newsletter widely has been difficult. MPML reaches many observers, but it does not necessarily reach other communities, such as the comet community, Comets-ML, IAU-related lists, or other users who may be interested in MPC updates. Most suggestions for sharing more MPC-related content were along the lines of “why don’t you send the newsletter to ...?”, which made it clear that we needed a more flexible and scalable way for people to subscribe.

Buttondown is designed specifically as a newsletter backend. It is a small independent business, and it seems to have been built with long-term stability in mind. At the same time, we are keeping backup copies of all MPC newsletters, and we have made sure that we can move to a different platform at any time if needed.

As part of moving to Buttondown, we have been copying over all the previous newsletters. They can be found on the Archive page. We have also customized the page with links to the MPC main website and to the Jira Helpdesk page. In our opinion, the most interesting feature of the Archive page is the Search option. This allows you to search for topics inside all the newsletters (e.g. ADES, Rubin, etc.).

Once you subscribe to the newsletter, it will appear directly in your inbox. The email is sent automatically as soon as the newsletter is published.

Subscribers can unsubscribe from the newsletter at any time. They can also leave comments on individual newsletter posts or contact us through Jira. For now, we have left the comments open, and we will see how this works in practice. Please note that we can close them at any time if things get out of hand.

We always encourage our users to contact us through the Jira Helpdesk and we are very grateful to the ones that have been doing that for a while.

If you are interested in receiving the MPC updates, please Subscribe to the Newsletter.

2. Jira Helpdesk

As many of you now know, the best way to contact the MPC is through the Jira Helpdesk. Before submitting a new ticket, please review the tips we have prepared on how to use Jira, as well as the frequently asked questions (FAQs). All MPC staff members have access to Jira, so please avoid emailing individual staff members. Urgent matters are more likely to be seen quickly by someone via the Helpdesk than if e-mailed to one person.

We encourage all users to report bugs and request new features through Jira. The more you communicate with us, the better we can understand how we are doing and where improvements are needed.

3. Comet processing: recent progress and next steps

Observations and orbits of comets

Comet processing has been an area of active development at the MPC over the past year. Each week, the MPC releases Observations and Orbits of Comets, a product that provides newly published comet observations together with updated comet orbits (see for example MPEC 2026-J11). A significant effort has been dedicated to automating this workflow. Until recently, however, because of the state of some of our database tables, the process still relied heavily on flat files as its main data source.

Recent work has focused on strengthening the quality-control checks around comet processing. Some important checks were missing, and we have now added additional safeguards for cases such as hyperbolic orbits, previously published observations, duplicate observations, and other potential inconsistencies.

During PREParation mode, or PREP mode, when the MPC is preparing the Minor Planet Circulars, we initially could not publish the weekly comet observation and orbit reports. In the past, when an update was needed or requested, ad-hoc updates were made for specific comets. A significant amount of work has now been done to address this limitation, and we are able to publish comet observations and orbits while in PREP mode. Since entering PREP mode on April 14, 2026, we have already successfully published five comet observation and orbit updates.

Comet identifications and numbering

Comet identifications and numbering remain more complicated than the corresponding processes for minor planets, mostly for historical reasons. For example, comet identifications can exist between two unnumbered comets, but these are not currently published in the DOU. This appears to be largely historical and also related to earlier limitations in what the MPC system could handle. We are working toward addressing this issue.

In the past, when a minor planet was identified with a numbered comet, the minor-planet designations were retired and the observations were reassigned to the numbered comet. We have decided not to continue using this approach. Instead, we will :

• “Cometify” the minor planet: that is, assign it a comet-style provisional designation by adding the appropriate C/ or P/ prefix, following the same process used for other minor-planet provisional designations when cometary activity is discovered;

• Link the new comet provisional designation to the primary provisional designations of the numbered comet.

This approach preserves the identification history more transparently while still allowing the comet designation to be connected to the appropriate numbered comet. One remaining task is to make this information easily accessible to users.

Comet numbering is also being revisited. Comets are numbered only when there are “enough oppositions,” but historically this has meant assigning a new designation to a new return, linking the designations, and then numbering the comet. This mechanism is largely historical: in the past, when a comet was observed at a new return, it was often difficult to immediately determine whether it was the same object observed on an earlier return. As a result, a new provisional designation was assigned for each return and the separate designations were linked later once the identification was confirmed. We are planning to update this process so that comet recoveries can be handled during PREP mode.

As the MPC prepares for the Rubin era, we need to continue modernizing our processes, including some that have remained largely unchanged for decades. These changes are not intended to overlook the history and complexities of comet dynamics. Rather, they are necessary steps toward making comet processing more efficient, more consistent, and better integrated with the rest of the MPC system.

None of these changes will happen overnight, and we will communicate each update at the appropriate time. This section is intended only as a high-level overview of the MPC’s plans for comet processing over the coming months.

Backfilling of Comet Orbits

In the past weeks we have backfilled all comet orbits in the mpc_orbits PostgreSQL table (for more information see past newsletters), and will continue checking for any few missing cases. We acknowledge that orbits for comet fragments are still missing from the table. We are also working on fixing database inconsistencies around comet observations and designations, improve the handling of observations and orbits of fragments, and make use of a new fragments table that we created to support this work.

Finally, we are working on Comet Automation Processing for objects on the PCCP. These efforts are all part of the ongoing work to make comet processing more automated, more robust, and better integrated with the rest of the MPC processing system.

4. How to access MPC data

MPC Explorer

In the past couple of years, as part of the ongoing work to update our existing services, we have been developing a replacement for the db_search functionality.

MPC Explorer is a user-friendly application that allows users to search for an object, resolve its identity, and retrieve its observations. At the moment, the service provides access to designations, observations and orbits and related documentation. We are working on adding discovery information.

MPC Explorer relies on MPC APIs, which are also accessible to our users, with related tutorials on how to use them.

Searches in the MPC Explorer can be performed using different types of designations, including object names, numbers, and provisional designations, both packed and unpacked, with or without spaces. Examples are provided in the Documentation tab. The service is designed to work with any object type: minor planets, comets and natural satellites.

The Designation tab returns packed and unpacked version of versions of the requested designation, together with additional information about identifications. For example, if the requested designation is a secondary designation, the service automatically returns the primary designation, along with the list of all secondary designations associated with it.

The Designation tab returns packed and unpacked version of versions of the requested designation, together with additional information about identifications. For example, if the requested designation is a secondary designation, the service automatically returns the primary designation, along with the list of all secondary designations associated with it.

The Observations tab returns observations in both ADES version 2022 and MPC-1992 format (informally called obs80). If you are not familiar with the ADES format or if you'd like to know more, please check our previous newsletters on the Archive page and use the Search feature to find all the newsletters that include the word ADES.

The Orbit tab returns orbital elements and orbital-related information (e.g. ephemeris used, non-gravitational information if available, photometric data and summary statistics).

Feedback and suggestion are always appreciated via Jira.

MPC replicated PostgreSQL tables

The MPC maintains an internal PostgreSQL database that contains, among other things, tables of observations and orbits. The observation table contains more than 500 million observations.

Some tables, which are part of the MPC’s internal PostgreSQL database, are also replicated to the Small Bodies Node; see the MPC Database page for more information. The replicated observations include all observations (for minor planets, comets and natural satellites) that have been validated through orbit fitting as belonging to a designated object, as well as observations in the Isolated Tracklet File. Additional information about the table, including the schema and examples of how to perform queries, is available on our website.

Instructions on how to replicate the tables are available from the SBN website. It is very important to carefully read the instructions, because maintaining a copy of our database table is not an easy task and it requires adequate resources.

The MPC strongly advise our users to not replicate the tables unless they are sure that they have the required resources and that they're able to maintain the replica. Please note that SBN has strict rule in place to drop the replica of any users that cannot keep up with the daily/weekly/monthly updates of the tables. The MPC is already providing multiple ways of accessing the data (see the MPC Explorer and the MPC APIs), but we are also working on creating more tools that some users have already required. In addition to our tool, SBN has been working for the past year on the MPC Advanced Queries Interface (MAQI).

MPC Advanced Queries Interface (MAQI)

For the past couple of years, the Small Body Node has been developing the MPC Advanced Queries Interface, or MAQI.

MAQI is an API and accompanying interface that allows authorized users to perform advanced queries on a PostgreSQL database maintained by the Small Bodies Node at the University of Maryland. This database continuously replicates the main database of the Minor Planet Center.

MAQI enables authorized users to perform complex queries on the MPC database, subject to time and resource constraints, and to download the results of those queries.

MAQI is now available at the following address: https://maqi.astro.umd.edu/ for all the users that would like to be beta-testers. Please note that:

• You need an account to access the service. To obtain an account, please contact ddarg at umd dot edu.

• SBN is still actively developing the tool and any feedback is welcome.

• This is not an MPC maintained services, hence for feedback, issues or bug reports, please contact ddarg at umd dot edu.

5. MPC User Group Meeting

The MPC User Group Meeting (MUG) took place on May 6–7, 2026, at the Center for Astrophysics in Cambridge, MA. We would like to thank the user group representatives for taking the time to share community feedback with us and for their constructive suggestions. We would also like to thank all users who sent valuable feedback to the MUG members.

The MPC is glad to see that the community thinks that MPC is overall doing okay (cit. from the community feedback). For those who are not familiar with the MUG, or who would like more information, please visit the MPC User Group page maintained by the Small Bodies Node. The page also contains a form for community feedback.

We always encourage all our users to use our Jira Helpdesk to share feedback with the MPC or report bugs and issues. MPC staff constantly monitor the Helpdesk.