Another successful course correction for New Horizons

New Horizons has successfully completed another course correction and is shipshape for its fly-by of Pluto on July 14.

A 45-second thruster burst on June 14 refined New Horizons’ trajectory toward Pluto, targeting the optimal aim point for the spacecraft’s flight through the Pluto system. This was only the second targeting maneuver of New Horizons’ approach to Pluto; Sunday’s burst adjusted the spacecraft’s velocity by just 52 centimeters per second, aiming it toward the desired close-approach target point approximately 7,750 miles above Pluto’s surface.

The maneuver was based on the latest radio tracking data on the spacecraft and range-to-Pluto measurements made by optical-navigation imaging of the Pluto system taken by New Horizons in recent weeks.

Right now all looks good for the fly-by.

New images from New Horizons of Pluto

Images taken by New Horizons over a four day period at the end of May show Pluto to be a planet with distinct areas of bright and dark.

The images are still very fuzzy and require a great deal of processing to tease out the detail that is seen. If anything, they resemble images of Mars taken from Earth before the space age. Thus, one must treat these the dark and light areas with great skepticism. We are seeing evidence of different surface topography and geology, but to pin it down more precisely at this time would be a mistake. The spacecraft has to get closer for us to know better what we are seeing.

Pluto’s moons rotate chaotically

Data from the Hubble Space Telescope has determined that two and maybe more of Pluto’s moons have chaotic rotations.

In a surprising new study, it has been found that two of Pluto’s moons, Nix and Hydra, are in a chaotic rotation. This means that an observer on Pluto would not see the same face of the moons from one night to the next. For visitors on the moons themselves, things would get even more confusing, as every day would be a different length to the one that preceded it. The other two moons studied, Kerberos and Styx, will likely be found to be chaotic too, pending further study.

This would also mean that you would not know where on the horizon the sun or Pluto would rise each day.

This information was gathered partly to help New Horizons prepare for its July 14 fly-by.

New Images of Pluto from New Horizons

Pluto in mid-May

Cool image time! New images taken by New Horizons of Pluto in mid-May have begun showing faint details of the planet’s surface.

“These new images show us that Pluto’s differing faces are each distinct; likely hinting at what may be very complex surface geology or variations in surface composition from place to place,” said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute in Boulder, Colorado. “These images also continue to support the hypothesis that Pluto has a polar cap whose extent varies with longitude; we’ll be able to make a definitive determination of the polar bright region’s iciness when we get compositional spectroscopy of that region in July.”

These images also suggest vaguely that Pluto might not be entire spherical, but I wouldn’t put much money on that speculation. We will know for sure in just a few more weeks.

New Horizons spots all of Pluto’s 5 known moons

New Horizons has now been able to image all of Pluto’s known moons.

Pluto’s five known satellites are Charon, Hydra, Nix, Kerberos and Styx. At 648 miles (1,043 km) in diameter, Charon is nearly half as wide as Pluto itself, but the other four moons are minuscule. Kerberos and Styx, for example, are thought to be just 4 to 13 miles (7 to 21 km) and 6 to 20 miles (10 to 32 km) wide, respectively.

That the spacecraft has been able to spot them all this soon bodes well for what it will see when if flies past Pluto in July.

A review of what little we know of Pluto prior to New Horizons’ arrival

The principle investigator of the New Horizons mission to Pluto gives us an overview of what is known, and what we might find, when the spacecraft does its fly-by on July 14.

Pluto has very distinct surface markings, including apparent polar caps, and it has an atmosphere (mostly nitrogen). We know that Pluto’s interior is primarily made of rock — about 70% by mass. Also, Pluto-Charon constitute a true binary planet, with a barycenter (center of mass) situated in the open space between them. We know Charon is a “rising star” among the solar system’s icy bodies, with evidence for recently created surface ices, possible internal activity (hinted at by the spectroscopic discovery of ammonium hydrates a few years ago), and some likelihood of an atmosphere itself — perhaps gas that was siphoned off Pluto! As for the small satellites — Styx, Nix, Kerberos, and Hydra — we know very little about them beyond their orbits and crude colors. Soon all six of those points of light, planet and moons, will be real worlds thanks to NASA’s New Horizons.

He also admits that trying to guess what we might find is quite hazardous, and likely will end up wrong.

Latest images from New Horizons see Pluto’s polar cap

Images taken between April 12 and April 18 by New Horizons of Pluto not only show one complete rotation of the planet as well as its moon Charon, the images also show a bright spot at Pluto’s pole that could be a polar cap.

The article calls it an “ice cap” but that is premature. At Pluto that cap could be made of a number of materials, not just water. We will not know until New Horizons gets closer.

New Horizons begins Pluto approach phase 2 of 3

It’s getting closer! On April 5 New Horizons began the second of three approach phases in preparing for its July 14 fly-by of Pluto.

During this phase, which lasts until June 23, the spacecraft’s instruments will take the first ever color and spectral photos of the Pluto system. Observations taken during this period will provide sharper focus of Pluto and its five moons. Long exposure images will scan the region for additional moons and a possible ring system. Ultraviolet observation of both the surfaces and atmospheres of Pluto and Charon will begin during this phase.

The main goal of these observations, besides gazing at Pluto and its five moons, is to scan the region that the spacecraft will pass through, and make sure there is nothing there that might pose a threat.

Want to help name Pluto’s features? You can!

The New Horizons science team is asking the public to help name the planet’s features it expects to see when the spacecraft flies past Pluto on July 14.

I should mention that the project scientist for New Horizons is Alan Stern, who also happened to be a major player in the private space effort called Uwingu, which previously offered the public the opportunity to name features on Mars, without IAU approval.

In the case of New Horizons, Stern is kind of forced to work with the IAU, since the project is funded by NASA and NASA would never challenge a fellow bureaucracy like IAU.

Week long movie of Pluto produced by New Horizons

Cool images! Using New Horizons’ long range camera scientists have compiled a movie showing Charon and Pluto orbiting each other during the last week of January 2015.

Pluto and Charon were observed for an entire rotation of each body; a “day” on Pluto and Charon is 6.4 Earth days. The first of the images was taken when New Horizons was about 3 billion miles from Earth, but just 126 million miles (203 million kilometers) from Pluto—about 30% farther than Earth’s distance from the Sun. The last frame came 6½ days later, with New Horizons more than 5 million miles (8 million kilometers) closer.

The wobble easily visible in Pluto’s motion, as Charon orbits, is due to the gravity of Charon, about one-eighth as massive as Pluto and about the size of Texas.

Our view of Pluto, and Charon, is only going to get better as New Horizons zooms towards its July fly-by.

New Pluto images from New Horizons

Pluto from 126 million miles

The New Horizons science team has finally released the navigation image of Pluto and Charon that the spacecraft took on January 25.

A cropped version is on the right. The image shows Pluto and its biggest moon Charon, with both appearing somewhat elongated in shape. Why this is so is not explained by the press release, but I suspect it is because the goal of the image was not sharpness but to locate the planet for navigation purposes.

New Horizons to begin observations of Pluto

In preparing for its July 14 fly-by of Pluto, New Horizons will take its first images of the planet on January 25.

Snapped by New Horizons’ telescopic Long-Range Reconnaissance Imager, known as LORRI, those pictures will give mission scientists a continually improving look at the dynamics of those moons. And they’ll play a critical role in navigating the spacecraft as it covers the remaining 135 million miles (220 million kilometers) to Pluto. “We’ve completed the longest journey any craft has flown from Earth to reach its primary target, and we are ready to begin exploring!” said Alan Stern, New Horizons principal investigator from Southwest Research Institute in Boulder, Colorado.

Over the next few months, LORRI will take hundreds of pictures of Pluto against star fields to refine the team’s estimates of New Horizons’ distance to Pluto. Though the Pluto system will resemble little more than bright dots in the camera’s view until May, mission navigators will use those data to design course-correction maneuvers that aim the spacecraft toward its flyby target point this summer. The first such maneuver could occur as early as March.

New Horizons awakes

After almost nine years of travel the American New Horizons probe has been successfully awakened in preparation for its July fly-by of Pluto.

Since launching on January 19, 2006, New Horizons has spent 1,873 days — about two-thirds of its flight time — in hibernation. Its 18 separate hibernation periods, from mid-2007 to late 2014, ranged from 36 days to 202 days in length. The team used hibernation to save wear and tear on spacecraft components and reduce the risk of system failures. “Technically, this was routine, since the wake-up was a procedure that we’d done many times before,” said Glen Fountain, New Horizons project manager at APL. “Symbolically, however, this is a big deal. It means the start of our pre-encounter operations.”

By mid-May we will begin to see images of Pluto and its moons that are better than any images ever before taken.

Three potential post-Pluto targets for New Horizons

After completing a deep search using the Hubble Space Telescope, scientists have identified three Kuiper Belt Objects (KBO) that New Horizons can actually reach after it flies past Pluto next year.

The KBOs Hubble found are each about 10 times larger than typical comets, but only about 1-2 percent of the size of Pluto. Unlike asteroids, KBOs have not been heated by the sun and are thought to represent a pristine, well preserved deep-freeze sample of what the outer solar system was like following its birth 4.6 billion years ago. The KBOs found in the Hubble data are thought to be the building blocks of dwarf planets such as Pluto.

I think it remarkable that in the vastness beyond Pluto they were able to find any objects that also happen to be within the narrow path that New Horizons must fly after it passes Pluto in July.

The planet debate continues

In a public debate about the scientific definition of a planet, the IAU’s definition, imposed about eight years ago to expressly prevent Pluto from being called one, was soundly defeated when the votes were counted.

Science historian Dr. Owen Gingerich, who chaired the IAU planet definition committee, presented the historical viewpoint. Dr. Gareth Williams, associate director of the Minor Planet Center, presented the IAU’s viewpoint [which is the definition that is presently considered official by scientific bureaucrats]. And Dr. Dimitar Sasselov, director of the Harvard Origins of Life Initiative, presented the exoplanet scientist’s viewpoint.

Gingerich argued that “a planet is a culturally defined word that changes over time,” and that Pluto is a planet. Williams defended the IAU definition, which declares that Pluto is not a planet. And Sasselov defined a planet as “the smallest spherical lump of matter that formed around stars or stellar remnants,” which means Pluto is a planet.

After these experts made their best case, the audience got to vote on what a planet is or isn’t and whether Pluto is in or out. The results are in, with no hanging chads in sight.

According to the audience, Sasselov’s definition won the day, and Pluto IS a planet.

Notice that two of the three debaters considered Pluto a planet even before the vote was taken. Notice also that the first debater, Gingerich, was on the very committee that the IAU had created to come up with a definition and then ignored completely when its definition decided that Pluto was a planet.

In the end, it will be the people who speak the language that will decide, not IAU bureaucrats. This little public relations event and vote tells me that the bureaucrats will lose.

Nothing for New Horizons after Pluto

As New Horizons begins its final shake-down in advance of its July 2015 flyby of Pluto, scientists have so far failed to find any Kuiper Belt objects in the right place for it to fly past after Pluto.

They haven’t given up hope, however. The search continues. As for the Pluto flyby,

The hibernating spacecraft will send weekly status beacons back to Earth, with wakeup scheduled for Dec. 7 to begin the final phase of its approach to Pluto. New Horizons will stay awake for two years to prepare for the encounter, fly by Pluto, and downlink science data. The craft’s appointment with Pluto is set for July 14, 2015, when it will zoom about 6,200 miles from the icy world’s unmapped surface for a one-shot chance to explore Pluto’s geology and atmosphere.

Hubble to search for Kuiper Belt targets for New Horizons

After completing a preliminary search for potential Kuiper Belt objects which the Pluto probe New Horizons might visit, scientists have decided to use the space telescope for a deeper more complete search.

As a first step, Hubble found two KBOs drifting against the starry background. They may or may not be the ideal target for New Horizons. Nevertheless, the observation is proof of concept that Hubble can go forward with an approved deeper KBO search, covering an area of sky roughly the angular size of the full Moon. The exceedingly challenging observation amounted to finding something no bigger than Manhattan Island, and charcoal black, located 4 billion miles away.

More here.

Designed and funded on the premise that it would fly past a Kuiper belt asteroid after it flew past Pluto, the New Horizons team has so far failed to find such an asteroid and is running out of time.

Designed and funded on the premise that it would fly past a Kuiper belt object (KBO) after it flew past Pluto, the New Horizons team has so far failed to find such an asteroid and is running out of time.

In theory, project scientists should have identified a suitable KBO long ago. But they postponed their main search until 2011, waiting for all the possible KBO targets to begin converging on a narrow cone of space that New Horizons should be able to reach after its Pluto encounter. Starting to look for them before 2011 would have been impossible, says Grundy, because they would have been spread over too much of the sky.

Now that the hunt for KBOs is on, the New Horizons researchers have mainly been using the 8.2-metre Subaru Telescope in Hawaii and the 6.5-metre Magellan Telescopes in Chile. They have found about 50 new KBOs; none is close enough for New Horizons to reach.

I always thought it unlikely that they would be able to, on the fly, find a suitable candidate that New Horizons could reach in the very empty vastness beyond Pluto. In fact, it seemed absurd and to me seemed instead a transparent public relations ploy to get the funding for the fly-by mission to Pluto. Sadly, my cynical perspective here appears to be turning out to be true.

The International Astronomical Union has rejected the first choice of voters for naming Pluto’s fourth and fifth moons.

The International Astronomical Union (IAU) has picked names for Pluto’s fourth and fifth moons, rejecting Vulcan, the first choice of the public.

After the discovery [of the moons], the leader of the research team, Mark Showalter (SETI Institute), decided to call for a public vote to suggest names for the two objects. To be consistent with the names of the other Pluto satellites, the names had to be picked from classical mythology, in particular with reference to the underworld — the realm where the souls of the deceased go in the afterlife. The contest concluded with the proposed names Vulcan, Cerberus and Styx ranking first, second and third respectively. Showalter submitted Vulcan and Cerberus to the IAU where the Working Group for Planetary System Nomenclature (WGPSN) and the Committee on Small Body Nomenclature (WGSBN) discussed the names for approval.

However, the name Vulcan had already been used for a hypothetical planet between Mercury and the Sun. Although this planet was found not to exist, the term “vulcanoid” remains attached to any asteroid existing inside the orbit of Mercury, and the name Vulcan could not be accepted for one of Pluto’s satellites (also, Vulcan does not fit into the underworld mythological scheme). Instead the third most popular name was chosen — Styx, the name of the goddess who ruled over the underworld river, also called the Styx.

I just can’t wait until there really is a robust population of space-faring colonists, if only because those colonists will then tell the IAU to go to hell when it tries to tell them what to name things.

Engineers have decided to keep the New Horizons spacecraft on its original fly-by path past Pluto, scheduled for July 2015.

Engineers have decided to keep the New Horizons spacecraft on its original fly-by path past Pluto, scheduled for July 2015.

The New Horizons team recently completed an 18-month study of potential impact hazards – mostly dust created by objects hitting Pluto’s small satellites – the spacecraft would face as it speeds some 30,000 miles per hour (more than 48,000 kilometers per hour) past Pluto in July 2015. The team estimated that the probability of a mission-ending dust impact was less than 0.3 percent if the spacecraft followed the current baseline plan, far below some early, more conservative estimates. So, with the concurrence of an independent review panel and NASA, the project team expects to keep New Horizons on this baseline course, which includes a close approach of about 12,500 kilometers (nearly 7,800 miles) from the surface of Pluto.

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