A bright fireball meteor streak captured by the NASA All Sky Fireball Network Camera located at Hiram College.
This illustration shows the position of NASA’s Voyager 1 and Voyager 2 probes, outside of the heliosphere, a protective bubble created by the Sun that extends well past the orbit of Pluto. Credits: NASA/JPL-Caltech
For the second time in history, a human-made object has reached the space between the stars. NASA’s Voyager 2 probe now has exited the heliosphere – the protective bubble of particles and magnetic fields created by the Sun.
Comparing data from different instruments aboard the trailblazing spacecraft, mission scientists determined the probe crossed the outer edge of the heliosphere on Nov. 5. This boundary, called the heliopause, is where the tenuous, hot solar wind meets the cold, dense interstellar medium. Its twin, Voyager 1, crossed this boundary in 2012, but Voyager 2 carries a working instrument that will provide first-of-its-kind observations of the nature of this gateway into interstellar space.
Voyager 2 now is slightly more than 11 billion miles (18 billion kilometers) from Earth. Mission operators still can communicate with Voyager 2 as it enters this new phase of its journey, but information – moving at the speed of light – takes about 16.5 hours to travel from the spacecraft to Earth. By comparison, light traveling from the Sun takes about eight minutes to reach Earth.
The most compelling evidence of Voyager 2’s exit from the heliosphere came from its onboard Plasma Science Experiment (PLS), an instrument that stopped working on Voyager 1 in 1980, long before that probe crossed the heliopause. Until recently, the space surrounding Voyager 2 was filled predominantly with plasma flowing out from our Sun. This outflow, called the solar wind, creates a bubble – the heliosphere – that envelopes the planets in our solar system. The PLS uses the electrical current of the plasma to detect the speed, density, temperature, pressure and flux of the solar wind. The PLS aboard Voyager 2 observed a steep decline in the speed of the solar wind particles on Nov. 5. Since that date, the plasma instrument has observed no solar wind flow in the environment around Voyager 2, which makes mission scientists confident the probe has left the heliosphere.
“Working on Voyager makes me feel like an explorer, because everything we’re seeing is new,” said John Richardson, principal investigator for the PLS instrument and a principal research scientist at the Massachusetts Institute of Technology in Cambridge. “Even though Voyager 1 crossed the heliopause in 2012, it did so at a different place and a different time, and without the PLS data. So we’re still seeing things that no one has seen before.”
In addition to the plasma data, Voyager’s science team members have seen evidence from three other onboard instruments – the cosmic ray subsystem, the low energy charged particle instrument and the magnetometer – that is consistent with the conclusion that Voyager 2 has crossed the heliopause. Voyager’s team members are eager to continue to study the data from these other onboard instruments to get a clearer picture of the environment through which Voyager 2 is traveling.
“There is still a lot to learn about the region of interstellar space immediately beyond the heliopause,” said Ed Stone, Voyager project scientist based at Caltech in Pasadena, California.
“Voyager has a very special place for us in our heliophysics fleet,” said Nicola Fox, director of the Heliophysics Division at NASA Headquarters. “Our studies start at the Sun and extend out to everything the solar wind touches. To have the Voyagers sending back information about the edge of the Sun’s influence gives us an unprecedented glimpse of truly uncharted territory.”
While the probes have left the heliosphere, Voyager 1 and Voyager 2 have not yet left the solar system, and won’t be leaving anytime soon. The boundary of the solar system is considered to be beyond the outer edge of the Oort Cloud, a collection of small objects that are still under the influence of the Sun’s gravity. The width of the Oort Cloud is not known precisely, but it is estimated to begin at about 1,000 astronomical units (AU) from the Sun and to extend to about 100,000 AU. One AU is the distance from the Sun to Earth. It will take about 300 years for Voyager 2 to reach the inner edge of the Oort Cloud and possibly 30,000 years to fly beyond it.
UPDATE: Saturday, October 20 — Tonight’s scheduled Open Night and local International Observe the Moon Night event is CANCELED. Weather again spoils our plans with showers and thunderstorms prowling the area, and tonight’s impending Wind Advisory keeping our dome closed. While weather is going to keep us indoors tonight, NASA has other suggestions on how you can observe and enjoy Earth’s Moon tonight and later! Take a look: Ten Ways to Observe the Moon, Some Can be Done Any Time
UPDATE: We are closely watching weather forecasts and, as so often has been the case this year, our Saturday night program appears in jeopardy with the possibility of rain and/or snow predicted. Check back here and watch our Twitter feed for further updates and a final go/no-go decision on our October 20 event.
Members of the public are invited to celebrate International Observe the Moon Night on Saturday, Oct. 20 from 7:00 to 9:00. The free event will be held at Stephens Memorial Observatory of Hiram College.
International Observe the Moon Night is an annual worldwide public event that encourages observation, appreciation and understanding of our Moon and its connection to NASA planetary science and exploration. The annual event connects scientists, educators, and lunar enthusiasts from around the world.
The Hiram event will (given clear skies) include amazing views of Earth’s Moon using the Observatory’s 1901 vintage telescope. If sky conditions allow, other wonders of the night sky will also be sought.
Cloudy skies at the scheduled starting time cancel the event and in that case, the observatory will not open. No reservations are required and there is no admission fee for observatory public nights.
The Observatory is located on Wakefield Road (Rt. 82) less than a quarter of a mile west of Route 700 in Hiram. There is no parking at the Observatory. Visitors may park on permissible side streets near the Post Office, a short distance east of the observatory.
Saturn’s rings are perhaps the most recognized feature of any world in our solar system. Cassini spent more than a decade examining them more closely than any spacecraft before it. Image Credit: NASA/JPL-Caltech/Space Science Institute
October 4, 2018: New research emerging from the final orbits of NASA’s Cassini spacecraft represents a huge leap forward in our understanding of the Saturn system — especially the mysterious, never-before-explored region between the planet and its rings. Some preconceived ideas are turning out to be wrong while new questions are being raised.
Six teams of researchers are publishing their work Oct. 5 in the journal Science, based on findings from Cassini’s Grand Finale. That’s when, as the spacecraft was running out of fuel, the mission team steered Cassini spectacularly close to Saturn in 22 orbits before deliberately vaporizing it in a final plunge into the atmosphere in September 2017.
Knowing Cassini’s days were numbered, its mission team went for gold. The spacecraft flew where it was never designed to fly. For the first time, it probed Saturn’s magnetized environment, flew through icy, rocky ring particles and sniffed the atmosphere in the 1,200-mile-wide (2,000-kilometer-wide) gap between the rings and the cloud tops. Not only did the flight path push the spacecraft to its limits, the new findings illustrate how powerful and agile the instruments were.
Many more Grand Finale science results are to come, but here are some of today’s highlights:
For the Cassini mission, the science rolling out from Grand Finale orbits more than justifies the calculated risk of diving into the gap — skimming the upper atmosphere and skirting the edge of the inner rings, said Cassini Project Scientist Linda Spilker.
“Almost everything going on in that region turned out to be a surprise,” Spilker said. “That was the importance of going there, to explore a place we’d never been before. And the expedition really paid off — the data is tremendously exciting.”
Analysis of Cassini data from the spacecraft’s instruments will be ongoing for years to come, helping to paint a clearer picture of Saturn.
“Many mysteries remain, as we put together pieces of the puzzle,” Spilker said. “Results from Cassini’s final orbits turned out to be more interesting than we could have imagined.”
The papers published in Science are:
On Oct. 4, as the Science publication embargo lifts, articles describing research complementary to these findings will post online in Geophysical Research Letters (GRL), a journal of the American Geophysical Union (AGU).
The night sky could look like this anywhere in Ohio if we would just be careful with artificial light. Image Credit: “Saving the Dark”
What do we lose when we lose sight of the stars? Excessive and improper lighting robs us of our night skies, disrupts our sleep patterns, and endangers nocturnal habitats. Saving the Dark explores the need to preserve or restore night skies and what we can all do to combat light pollution. This film will be shown October 5 & 6 at the Chagrin Documentary Film Festival
Click here for more information and to view the film’s trailer.
FINAL — 8:59 PM: Event canceled due to near-Overcast conditions and nearby rain showers. We will try again in July.
UPDATE – June 23, 4:00 PM: Sky conditions are very changeable but prospects look generally poor for tonight’s scheduled Open Night as clouds dominate and isolated showers roam the region. We will make a final go/no-go decision this evening and announce it here and via Twitter.
Stephens Memorial Observatory of Hiram College will be open for public observing Saturday, June 23, from 9:00 to 11:00 PM. Given good skies, visitors will see wonderful views of the Moon and giant planet Jupiter with moons of its own. Other objects of interest, such as star clusters, will also be sought, using the Observatory’s vintage telescope.
Jupiter and Moons – June 23, 2018, 10 PM – Simulated View
The June event represents a late start to our public outreach season caused by an operational problem with the observatory building constructed in 1939. The problem has been corrected and we hope to present a full season’s schedule of public events.
Cloudy skies at the scheduled starting time cancel the event and in that case, the observatory will not open. No reservations are required and there is no admission fee for observatory public nights.
The Observatory is located on Wakefield Road (Rt. 82) less than a quarter of a mile west of Route 700 in Hiram. There is no parking at the Observatory. Visitors may park on permissible side streets near the Post Office, a short distance east of the observatory.
We normally re-open from our winter break in March or at latest, April. You may have noticed clear or clear-ish nights have been fairly rare and the trend continues so we have not yet scheduled anything for 2018. We will endeavor to begin our public observing events in May though now we are encountering issues with our old building. Weather? Building? It’s always something! Stay tuned here and via Twitter for program announcements and we will hope for the best.
