Blue Ghost just completed its mission, which lasted a full lunar day — two Earth weeks — on the near side of the moon.

The spacecraft, about the size of a small car, conducted a series of experiments. It drilled three feet into the lunar soil, took X-ray images of the magnetic bubble that surrounds and protects Earth and sought a mysterious yellow glow at sunset.

Built by Firefly Aerospace, a startup in Texas, Blue Ghost was launched from Earth in January and pulled into orbit around the moon in mid-February. A couple of weeks later, it took this video, sped up by a factor of 10, as it circled 62 miles above the surface. The shiny sheets are radiator panels that protected the spacecraft from the extreme heat while in sunshine.

Landing

In the early hours of March 2, Blue Ghost fired its engine to drop it out of orbit, falling toward the moon. Just over an hour later, it was on the surface in Mare Crisium, a lava plain inside an ancient 345-mile-wide impact crater in the northeast quadrant of the near side of the moon.

Blue Ghost became the first completely successful landing by a commercial company, and Firefly achieved that on its first try.

Several companies and countries have aimed to land on the moon in recent years. The map below shows the crewed Apollo moon landing sites, as well as more recent robotic landings from China, India, Japan and commercial companies. Recent crash sites from failed landings are also shown.

China has a 100 percent success rate with four successful Chang’e robotic landings, but many other missions have crashed.

The failures include Hakuto-R Mission 1, from Ispace, a Japanese company; Beresheet, from an Israeli nonprofit; Luna 25, from Russia; and Chandrayaan-2, from India. (India’s second try, Chandrayaan-3, was successful.)

Three other landers — SLIM, from the Japanese space agency, and Odysseus and Athena, from Intuitive Machines of Houston — landed and communicated back to Earth, but their success came with an asterisk. All three toppled over after landing.

Experiments

While Firefly built and operated Blue Ghost, NASA sponsored the mission, part of the agency’s efforts to tap into commercial ventures to send its scientific cargo to space at lower costs. NASA paid Firefly $101.5 million to carry 10 science and technology payloads to the lunar surface.

Blue Ghost landed at lunar sunrise so that the solar-powered spacecraft could operate for the longest possible duration.

One of Blue Ghost’s payloads, PlanetVac, demonstrated a technology to simplify the collecting of soil and rocks. It fired a blast of gas into the ground, which propelled material into a container. This technology will be used on a Japanese mission, Martian Moons Exploration, which will collect samples from Phobos, a moon of Mars, and bring them back to Earth for study.

Another experiment, Lunar Magnetotelluric Sounder, flung four sensors, each a little smaller than a soup can, in directions at 90-degree angles to one another (like north, south, east and west on a compass). The sensors landed about 60 feet away, and, connected by cables to the lander, measured voltages — essentially a supersized version of a conventional voltmeter. An eight-foot-high mast shot upward, lifting an instrument to measure magnetic fields. The experiment gathered data about naturally occurring currents inside the moon, which provides hints about what the moon is made of down to 700 miles below the surface.

A pneumatic drill used bursts of nitrogen gas to blow away soil and rock, reaching three feet below the surface. A probe measured temperatures and the flow of heat from the moon’s interior.

Solar Eclipse

While people on Earth were taking in a blood moon and a total lunar eclipse on the evening of March 14, Blue Ghost witnessed and photographed a total solar eclipse.

During the eclipse, temperatures dropped from 100 degrees Fahrenheit to minus 270 degrees. The spacecraft relied on battery power to continue operating through five hours of near-total darkness.

This image shows the “diamond ring effect” as the sun began to emerge from behind Earth.

Sunset

On March 16, the sun began to set and the lunar day was nearly over. Before its mission ended, Blue Ghost snapped high-resolution images of the scene. It was more than a few final pretty snapshots. Scientists are hoping the pictures can help solve an enduring scientific mystery of the lunar horizon glow.

Eugene Cernan, the commander of Apollo 17 who in 1972 was the last man to walk on the moon, sketched observations of a glow along the horizon before sunrise. However, that phenomenon is not easily explained because the moon lacks an atmosphere to scatter light.

Signoff

This was the last message from the Blue Ghost spacecraft, about five hours after sunset:

The spacecraft was not designed to survive the bitter cold of the lunar night. But another lunar mission, Japan’s SLIM spacecraft, surprised engineers last year by riding out several lunar nights. In early April, after the sun rises again, Firefly will listen for radio messages from Blue Ghost, just in case it does revive.

The Tuolumne County Public Health Department on Wednesday confirmed two measles cases a day after it opened an investigation into the possible infections.

The department said the cases involved an adult and a child under 18 who lived in the same household and had traveled internationally. It’s unclear whether they had been vaccinated against measles, a highly contagious and potentially deadly disease most often associated with a high fever and rash.

On Tuesday, the department said it was investigating the cases for measles and warned of potential exposure at Summerville High School in Tuolumne on March 10-11 and at Adventist Health Sonora Emergency Department on the evening of March 15 and morning of March 16.

Public health officials issued another update Thursday night warning those who visited the Sonora Sports and Fitness Center’s back gym, locker rooms, restrooms and back pool area on March 10 between 3 p.m. and 7 p.m. of possible exposure.

“We understand that there may be a lot of questions and concerns. The investigation is still ongoing, and we will provide updates as they are available,” Michelle Jachetta, the county’s public health director, said in a Wednesday statement confirming the cases. “We want to remind the public that measles is a highly contagious disease and to take steps to protect yourself and your family by ensuring current vaccination status for measles, monitoring for symptoms, and staying home when you feel sick.”

Michael Merrill, superintendent of Summerville Union High School District, also issued a statement this week that saying the district “takes the health and safety of its students, staff and our community seriously” and that the school would work with public health officials “through the process of identifying any risk.” More than 430 students attend Summerville High School, according to its website.

Tuolumne County’s cases come amid a deadly measles outbreak that began in the southern Plains and Panhandle region of Texas in January and has since infected 279 people, making up the vast majority of more than 300 confirmed cases across 15 states so far this year. An unvaccinated school-aged child in Texas died from the disease in February.

The California Department of Public Health reported Thursday that there have been at least eight confirmed cases of measles in the state this year. They have not published the locations of the cases.

Tuolumne County reported some of the state’s lower vaccination rates in the 2023-24 school year, according to data published this week by the state public health department.

Only 89.8% of Tuolumne County kindergarten students were up to date on all their immunizations, compared with 93.7% of kindergartners statewide. And only 93.1% of kindergarten students had received both doses of their measles, mumps and rubella shots, substantially lower than the 96.2% statewide average. California typically publishes vaccination rates for kindergarten, first-grade and seventh-grade students.

Public health experts say a 95% vaccination rate, sometimes called “herd immunity,” is considered the gold standard of disease prevention. A slip of even 1 or 2 percentage points can create an opportunity for disease to spread, meaning that even if the overwhelming majority of children are vaccinated, it could still take only a few cases to spark an outbreak in an area where immunization rates have fallen below 95%.

California reported a decline last year in the share of kindergarten students who were immunized against measles, despite strict laws that make it difficult for parents to skip shots for their children. That includes 16 counties where measles immunization had fallen below the herd immunity threshold.

An increase in vaccine hesitancy in recent years, coupled with widespread disinformation online and increasing political division, could make it even harder to encourage immunization, said former state Sen. Richard Pan, a Sacramento Democrat who wrote California’s vaccine laws.

“We seem to be heading the wrong direction,” Pan said. “We’ve been feeling pretty comfortable, like ‘we’re OK.’ But we suddenly now prove to people, it’s not OK.”