On July 1st, 2025, the Asteroid Terrestrial-impact Last Alert System (ATLAS) station announced the detection of another interstellar object (ISO) passing through our Solar System. Following on the heels of 1I/’Oumuamua in 2017 and 2I/Borisov in 2019, 3I/ATLAS became the third ISO to be witnessed by astronomers in the space of eight years. Like 2I/Borisov, this latest visitor began venting gas and dust as soon as it began approaching the Sun, indicating that it was clearly a comet.

But in keeping with the notion that extraterrestrials could be sending probes to interstellar space, scientists conducted a technosignature search of this object, just to be sure (much as they had of 1I/’Oumuamua and 2I/Borisov). In a recent study, a team led by researchers at the SETI Institute released the results of their survey, which “did not find any signals worthy of additional follow-up.” Nevertheless, the study set upper limits on radio detection that will come in handy the next time an ISO comes around.

The team was led by Sofia Sheikh, a Technosignature Research Scientist and NSF MPS-Ascend Fellow and multiple researchers from the SETI Institute. They were joined by researchers from Breakthrough Listen, the Berkeley SETI Research Center, the Jodrell Bank Center for Astrophysics (JBCA), and multiple universities worldwide. The paper detailing their findings appeared in The Astronomical Journal.

*The ATA at the Hat Creek Observatory in Northern California. Credit: Seth Shostak/SETI Institute*

Interstellar objects (ISOs) present a rare opportunity for astronomers to study how other planetary systems form and evolve. Since asteroids and comets are essentially leftover material from the formation of planets, their composition can tell scientists a lot about other star systems, without the burden of having to send missions there. Since humanity has an established history of sending probes to interstellar space – Pioneer 10* and 11*, Voyager 1* and 2*, and the New Horizons mission – there is always the possibility that an interstellar visitor could be an extraterrestrial messenger.

Scientists at the SETI Institute examined 3I/ATLAS for signs of technological activity (technosignatures) using the Allen Telescope Array (ATA) at the Hat Creek Radio Observatory. As they report in their study, they scanned the ISO for more than 7 hours across a wide range of radio frequencies – covering 1 to 9 gigahertz (GHz). This broad range allowed them to search for narrowband radio signals not found in nature, which would be evidence of technology.

The team initially identified 74 million narrowband signals, which were then filtered to eliminate radio-frequency interference (RFI). From this, they identified 211 signals of interest, which were visually inspected in the time-frequency domain. None of these were found to be artificial in nature, which was expected, given the composition and behavior of the object. As Dr. Sheikh said in a SETI Institute release:

Eventually, our own Voyager spacecraft will be extraterrestrial artifacts in other stellar systems. Given that, it is important that we understand the natural distribution of interstellar objects so that we will be able to identify any anomalies that could one day be signs of an artificial interstellar object.

While no technosignatures were found, the observations place upper limits on the power of any radio transmitter on or near 3I/ATLAS. Specifically, they ruled out signals stronger than about 10-110 watts over the detected frequencies. The study also demonstrates the ATA’s rapid response to new interstellar objects, given that observations began less than a day after 3I/ATLAS was first detected.

*Artist’s impression of interstellar comet 2I/Borisov. Credit: NRAO/AUI/NSF, S. Dagnello*

According to co-author Valeria Garcia Lopez, a physics professor at Furman University and a member of Breakthrough Listen at UC Berkeley, this demonstrated the capabilities of modern instruments in identifying possible technosignatures. “The results from 3I/ATLAS show how realistic it is to detect a signal with the technology we have today,” she said. “That is why it is important to keep searching for technosignatures, even from objects we might not expect to have signals.”

The study of ISOs also helps scientists better understand the natural properties of objects that are regularly ejected from star systems. It also allows them to probe the interstellar medium (ISM) by examining the effects billions of years of traveling through space have on these objects. As more ISOs are discovered, each presents a new opportunity to learn more about the cosmos and to search for possible evidence of extraterrestrial civilizations.

Further Reading: SETI Institute, The Astronomical Journal

Los Angeles City Councilmember Nithya Raman cut deeper into the lead of reality television personality Spencer Pratt on Saturday, as his lead slimmed to just a single percentage point.

Pratt fell to just over 27% of the vote while Raman jumped up to slightly over 26%, according to the results from the Los Angeles County Registrar-Recorder. Pratt now leads Raman by just 7,494 votes.

“We’ve seen Nithya Raman catching up on every update and the last two in particular she’s accelerated,” said Paul Mitchell, vice president of the bipartisan voter data firm Political Data Inc. “She’s continued to gain at a rate that means she will eventually catch up unless Pratt starts getting some ballots coming in that are either geographically or demographically better for him.”

Democratic consultant Michael Trujillo, who doesn’t represent anyone in the mayoral race, said the results suggest Raman will surpass Pratt as more votes are counted.

“I think it’s over,” Trujillo said. “It appears Nithya will be in the runoff. Pratt doesn’t appear to be growing much more than what the Trump base vote was and we’ll probably get an update tomorrow showing that.”

The second-place finisher in the mayoral primary will face Mayor Karen Bass in a Nov. 3 runoff. On election night Tuesday, the Associated Press determined that Bass had secured enough votes to qualify for the runoff.

Pratt has been in second place since then, but Raman has gradually eroded his lead as mail-in ballots have been counted. The updated vote tally released Thursday showed Pratt with 29% of the vote and Raman with 23%.

With Friday’s update, Raman’s share had risen to 25% and Pratt’s shrank to 28%, for a 3 percentage point gap.

In the most recent batch of mail-in ballots counted, Raman received 23,514 votes, while Pratt gained 10,336.

Election analysts expected Raman to gain ground as the mail-in ballots were tallied, reasoning that many left-of-center voters — Raman’s base — held onto their mail-in ballots until the last minute as they waited to choose between Democratic gubernatorial candidates. They also say younger, more progressive voters tend to hold onto their ballots longer generally.

Although the mayor’s race is nonpartisan, Pratt is a Republican in a city that is overwhelmingly dominated by Democratic voters and elected officials.

A poll by the UC Berkeley Institute of Governmental Studies, which was co-sponsored by The Times, had Pratt running in third place behind Bass and Raman.

The poll of 1,351 likely voters conducted May 19-24 had Bass with 26% support, Raman with 25% support and Pratt with 22% support, with a 3% margin of error.

Los Angeles voters have become accustomed to seeing election results change as late-arriving ballots are tabulated. In the 2022 mayoral primary, real estate developer Rick Caruso led the pack for about a week before Bass pulled ahead.

Pratt was favored in many of the same neighborhoods that voted for Caruso, according to a Times analysis of precinct-level returns provided by the Los Angeles County Registrar-Recorder on Wednesday, when an estimated 62% of the projected vote had been counted. Raman, by comparison, made inroads in progressive areas dominated by Bass four years ago.

Pratt, whose Pacific Palisades fire home burned in the January 2025 fire, was strong there and on the Westside, as well as in the San Fernando Valley communities of Encino, Woodland Hills, Chatsworth and Sunland-Tujunga.

Raman dominated precincts known for their progressive politics, particularly those with younger people in renter-heavy neighborhoods stretching from Hollywood to Highland Park, including her home base of Silver Lake.

Mail-in ballots with an election day postmark will continue to be accepted by county election officials through Tuesday.