Nearly eight years after its historic Pluto flyby, NASA’s New Horizons probe is getting ready for another round of observations made from the icy edge of the solar system — and this time, its field of view will range from Uranus and Neptune to the cosmic background far beyond our galaxy.
Scientists on the New Horizons team shared their latest discoveries, and provided a preview of what’s ahead, during this week’s Lunar and Planetary Science Conference in The Woodlands, Texas.
In a recent study scheduled to be published in the journal Icarus in March 2023, a team of researchers led by the Southwest Research Institute (SwRI) modeled a potential correlation between an ancient freezing ocean with cryovolcanic flows and surface canyons on Pluto’s largest moon, Charon. Their hypothesis was that when Charon’s interior ocean froze long ago, the significant stress put on the icy outer shell from the addition of more ice to the bottom of the existing shell could have been responsible for the cryovolcanic flows on the surface.
We previously examined how Neptune’s largest moon, Triton, could answer the longstanding question: Are we alone? With its nitrogen geysers discovered by NASA’s Voyager 2 spacecraft, possible interior ocean, and lack of craters, Triton could be geologically active, which makes it an excellent celestial body for future astrobiology missions. But Triton isn’t the only place on the edge of the solar system which garners interest for finding life beyond Earth, as one of the most familiar and well-known (former) planets also exhibits evidence of recent geological activity and crater-less surface features. This is everyone’s favorite dwarf planet, Pluto, which like Triton has only been visited by one spacecraft, this one being NASA’s New Horizons, in 2015. But even with only one visitation, we discovered so much about Pluto, and what it might be hiding, as well.
Over seven years ago, the New Horizons mission made history when it became the first spacecraft to conduct a flyby of Pluto. In the leadup to this encounter, the spacecraft provided updated data and images of many objects in the inner and outer Solar System. Once beyond the orbit of Pluto and its moons, it embarked on a new mission: to make the first encounter with a Kuiper Belt Object (KBO). This historic flyby occurred about four years ago (Dec. 31st, 2015) when New Horizons zipped past Arrokoth (aka. 2014 MU69).
Now that it is passing through the Kuiper Belt, away from the light pollution of the inner Solar System, it has another lucrative mission: measuring the brightness of the Universe. These measurements will allow astronomers to make more accurate estimates of how many galaxies there are, which is still the subject of debate. According to new measurements by New Horizons, the light coming from stars beyond the Milky Way is two to three times brighter than the light from known populations of galaxies – meaning that there are even more out there than we thought!
Pluto’s largest moon, Charon, started off as a beautiful, smooth red grape until someone came along, mostly peeled it, tried to smoosh it, then just gave up and walked away, leaving the poor moon to look like the absolute travesty that it is. Okay, so maybe that’s not exactly what happened, but Charon just looks like a mess and scientists want to know why. Never mind its smooshed equator, but what’s the deal with its red cap? Where did it come from and why is it red?
NASA has granted mission extensions to eight different planetary missions, citing the continued excellent operations of the spacecraft, but more importantly, the sustained scientific productivity of these missions, “and the potential to deepen our knowledge and understanding of the solar system and beyond.” Each mission will be extended for three more years.
After New Horizons made its close flyby of Pluto in July of 2015, scientists were astounded at the incredible closeup views of Pluto’s surface. One of the most intriguing and mysterious features was a bright plain inside the prominent heart-shaped feature on Pluto, called “Tombaugh Regio” (Tombaugh Region) named after Clyde Tombaugh, who discovered Pluto in 1930.
The region is composed of a broken surface of irregularly-shaped segments that appear to be geologically young because no impact craters are part of the terrain.
The New Horizons spacecraft has been speeding away from Earth since it launched in 2006. Scientists using the Alice UV imaging spectrograph on board New Horizons, have been patiently but sporadically gathering data during those 15 years, but also waiting to get far enough away from the Sun to make a specific measurement: the brightness of the Lyman-alpha background of the Milky Way. Until now, this had never been measured accurately.
Blasting out of Mos Eisley Space Port, the Millennium Falcon carries our adventurers off Tatooine bringing Luke Skywalker across the threshold into space. With Imperial Star Destroyers closing, Luke bemoans Han Solo’s delay in jumping to Hyperspace. It takes time to make these calculations through the Falcon’s “Navicomputer.” Han explains that otherwise they could “fly right through a star” or “bounce too close to a supernova.” (probably the same effect of each – also are supernovas bouncy?)
Celestial calculations are needed to figure out where you’re going. In Star Wars these are done by ship computers, or later by trusty astromech droids like R2-D2. But, for the first time, simulations have been conducted of an uncrewed ship’s ability to autonavigate through interstellar space. While not at Hyperspace speeds, the simulations do account for velocities at up to half the speed of light. Created by Coryn A.L. Bailer-Jones of the Max Plank Institute for Astronomy, these simulations may be our first step to creating our own “Navicomputers” (or R2-D2s if they have a personality).