Enlarge / An artist's illustration of NASA's two Janus spacecraft as they would have appeared in space. (credit: Lockheed Martin )

Two small spacecraft should have now been cruising through the Solar System on the way to study unexplored asteroids, but after several years of development and nearly $50 million in expenditures, NASA announced Tuesday the probes will remain locked inside a Lockheed Martin factory in Colorado.

That’s because the mission, called Janus, was supposed to launch last year as a piggyback payload on the same rocket with NASA’s much larger Psyche spacecraft , which will fly to a 140-mile-wide (225-kilometer) metal-rich asteroid—also named Psyche—for more than two years of close-up observations. Problems with software testing on the Psyche spacecraft prompted NASA managers to delay the launch by more than a year.

An independent review board set up to analyze the reasons for the Psyche launch delay identified issues with the spacecraft’s software and weaknesses in the plan to test the software before Psyche’s launch. Digging deeper, the review panel determined that NASA’s Jet Propulsion Laboratory, which manages the Psyche mission, was encumbered by staffing and workforce problems exacerbated by the COVID-19 pandemic.

Enlarge / Home sweet home. (credit: SCIEPRO/Getty)

On August 25th, 2012, humanity became an interstellar species. There was no fanfare or galactic welcome party as a humble robotic probe, the Voyager 1 spacecraft, crossed an invisible threshold. It slipped between the region dominated by the physics of the Sun and into the thin milieu of plasma between the stars.

Whatever fate befalls us now, whatever future civilizations rise and fall, whether we heal the Earth or continue our self-destructive path, we will still, and always, have this. A monument, a marker, a testament to the existence of our species and the ingenuity of our minds. It’s unlikely that any alien civilization will encounter our spacecraft, yet it will still exist, circling the center of the Milky Way for eons to come.

In the coming decades, Voyager 1 will be joined by other craft sent along solar-escape trajectories: the Pioneer probes, New Horizons, and more. And now that we’ve crossed this astrophysical threshold, we are forced to ask a difficult question: Is this it? Is this all we’ll ever accomplish beyond the Solar System, a scattering of wayward probes sent out into the infinite night?

Saturn might be the planet in our Solar System best known for its spectacular rings, but the icy giant Uranus also has a system of 13 nested rings. Eleven of those rings—nine main rings and two fainter dusty rings—are clearly visible in the latest spectacular image from NASA's Webb Space Telescope. Future images should reveal the remaining two faint outer rings discovered with the Hubble Space Telescope in 2007.

"Uranus has never looked better. Really," NASA tweeted . "Only Voyager 2 and Keck (with adaptive optics) have imaged the planet's faintest rings before, and never as clearly as Webb’s first glimpse at this ice giant, which also highlights bright atmospheric features."

As we've reported previously , the Webb Telescope launched in December 2021 and, after a suspenseful sunshield and mirror deployment over several months, began capturing stunning images. First, there was the deep field image of the Universe, released last July. This was followed by images of exoplanet atmospheres, the Southern Ring Nebula, a cluster of interacting galaxies called Stephan's Quintet, and the Carina Nebula, a star-forming region about 7,600-light-years away. These images reportedly brought astronomers to tears.

Enlarge / A perspective view across Maat Mons on Venus, based on Magellan radar data. (credit: NASA/JPL)

Venus is almost the same size, mass and density as Earth. So it should be generating heat in its interior (by the decay of radioactive elements) at much the same rate as the Earth does. On Earth, one of the main ways in which this heat leaks out is via volcanic eruptions. During an average year, at least 50 volcanoes erupt.

But despite decades of looking, we’ve not seen clear signs of volcanic eruptions on Venus – until now. A new study by geophysicist Robert Herrick of the University of Alaska, Fairbanks, which he reported this week at the Lunar & Planetary Science Conference in Houston and published in the journal Science , has at last caught one of the planet’s volcanoes in the act.

It’s not straightforward to study Venus’s surface because it has a dense atmosphere including an unbroken cloud layer at a height of 45-65 km that is opaque to most wavelengths of radiation, including visible light. The only way to get a detailed view of the ground from above the clouds is by radar directed downward from an orbiting spacecraft.

Enlarge / An artist's interpretation of Voyager 2, pointed to transmit data to Earth. (credit: NASA/JPL-Caltech )

People probably suspect that having no data is the worst frustration for scientists. In reality, having just a single source of data can be worse, since you don't know how typical that lone example might be. But the worst situation is to have two sources of data that don't entirely agree, leaving you with the challenge of trying to determine what causes the differences.

That situation is where the scientists who work with data from NASA's Voyager probes find themselves in the wake of Voyager 2 reaching interstellar space last year, making it the second spacecraft we've built that has made it there. Now, in a series of five papers, researchers have attempted to compare or contrast the data from the two Voyagers and try to make sense of the contradictions, knowing that we've got nothing built that's going to get new data from that distance any time soon.

At the edge of the Solar System

The Sun's gravitational influence extends out to the edge of the Oort cloud, over three light years from the Sun. But the Sun influences its environment in ways that go beyond simple gravity. It generates an enormous magnetic field that extends well beyond the planets and emits a stream of charged particles that stream out toward interstellar space. These influences are limited by the influence of our galaxy, which has its own magnetic field and an interstellar medium full of its own charged particles.

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