IBEX is a spacecraft (Interstellar Boundary Explorer) that is observing the Solar System boundary. It will do this by collecting particles that travel from Pluto toward Earth, which will help scientists learn more about the boundary of our Solar System.
IBEX has a network of receivers on Earth that are constantly receiving signals from the spacecraft. These are then sent to Mission Control Center in Dulles, Virginia and the IBEX Science Operation Center in San Antonio, Texas.
IBEX is a spacecraft
IBEX is a spacecraft that collects particles. These particles come from the boundary of our solar system and beyond – from the interstellar medium. IBEX has two sensors that collect these particles as the satellite orbits the Earth.
These particles have energy levels that range from very low to high. The higher-energy particles can be seen by IBEX’s Hi sensor and lower-energy particles are picked up by its Lo sensor. These particles help scientists understand the boundaries of our solar system and the interstellar medium.
The particles that IBEX detects are the result of a violent collision between charged particles in the solar wind and neutrals from the interstellar medium. The charged particles snatch electrons from the cool neutral gas ions, creating energetic neutral atoms (ENAs).
To detect the ENAs, IBEX’s sensors use echolocation properties that are similar to those used by bats. This technique helps the team detect the exact location of the particles that they collect.
Researchers used IBEX’s measurements to create a map of the edges of the heliosphere, the region of space where our solar system connects to the rest of the universe. The study, led by Dr. Dan Reisenfeld of Los Alamos National Laboratory, published in the June 10, 2021 issue of Astrophysical Journal Supplement Series, revealed how solar winds muscle their way out into interstellar space.
This interaction between the Sun’s solar wind and interstellar space allows scientists to trace the heliosphere’s boundary, which separates our planet from the stars. This area is a vital part of our solar system, and IBEX is helping to reveal the mysteries that lie there.
When IBEX’s telemetry signal returns to Earth, scientists can analyze the information in detail. The signals are sent in radio waves, and the team has a global network of receivers that can receive them.
Scientists can then use these measurements to figure out the heliosphere’s shape, size and other key details. They can also calculate how the heliosphere moves, and how fast it is moving.
For example, they discovered that the heliosphere doesn’t have a “bow shock” that would normally form as it plows through space and pushes particles out of the way. The lack of bow shock is a result of the way that the heliosphere’s boundary interacts with magnetic forces. This is a key finding in understanding how the heliosphere is formed and what happens to the solar system as it leaves our planet.
It collects particles
IBEX collects particles that come from the boundary of our solar system and beyond – from the interstellar medium. Instead of collecting light, IBEX’s sensors and spacecraft measure the direction, mass, and energy of these particles.
The particles that IBEX detects are called energetic neutral atoms, or ENAs. They are produced when zippy solar wind particles collide with lumbering interstellar atoms.
When the zippy particles collide, they steal electrons from the lumbering atoms. Then they become neutral themselves. They take two to three years to journey from the sun’s heliosphere all the way to IBEX if they are traveling in the right direction.
Eventually, some of these energetic neutrals hitch a ride back into the heliosphere. They spend another six months roiling through the heliosheath, the gap between the heliosphere’s outer boundaries.
As they cruise through the heliosphere, these energetic neutrals may collide with passing charged particles, losing an electron and becoming tied to the surrounding magnetic field. Then they might travel across the heliopause, the edge of the heliosphere where the rays of the sun are no longer visible.
A group of energetic neutrals may also drift out into interstellar space, where they will pick up a taste of the Local Fluff, cruising in this distant region of space until they inevitably collide with slower particles. This time, they might snag an electron from the lumbering interstellar atoms, and become neutral again.
When they re-enter the heliosphere, the energetic neutrals float along at a slower speed than when they left, but still faster than the solar wind. They might spend another six months roving the chaotic heliosheath, where they could pick up a taste of the Local Fluff again.
Once they have a taste of this lulling local environment, some energetic neutrals might decide to stay there. They’ll snag a second electron from the lumbering interstellar particles, and become neutral again.
If they aren’t destined for IBEX, these energetic neutrals might continue their long trip beyond the heliosphere to another galaxy. There, they’d mix with a new population of cosmic rays, which are similar to the solar wind but at much lower energies.
It communicates with Earth
IBEX communicates with Earth by sending signals through the planet’s magnetic field. Each time the spacecraft completes one orbit, it will spend a few days inside the Earth’s magnetosphere. During this time, it does not need as much power to send radio signals as it does when it is outside the magnetosphere, and Earth’s receivers can receive the signal from IBEX.
The IBEX team uses a global network of receivers to accept radio signals from the satellite. This is important because it can help ensure that the IBEX team gets a good reception from all parts of the globe.
Using these receivers, IBEX scientists can send data back to Earth. This includes information about what the spacecraft has gathered, such as how fast interstellar particles are accelerating towards the Solar System. The data also includes the direction in which the particles are traveling, as well as their energy.
IBEX scientists are looking at what happens to interstellar particles that come to the Solar System. These are called energetic neutral atoms (ENAs). IBEX’s sensors collect these particles, which are similar to the kind of rays that enter the heliosphere from outer space.
These particles travel to the Solar System at a very low speed, and so they do not form a bow shock as they move through the heliosphere. They also come in a different direction than the particles from outer space, probably due to the fact that the heliosphere’s boundary is magnetically charged.
Another thing the IBEX team has been studying is the plasma sheet and the magnetotail, which form near the heliosphere’s boundaries and help the atoms that make up the solar wind travel around the Sun. The IBEX team has observed the plasma sheet for the first time, and it is very dynamic, ranging from flat and static to flowing and twisting.
Scientists are wondering whether these dynamic features are caused by the reconnection of ions from the plasma sheet to the magnetotail. “It’s really exciting,” McComas says. The IBEX team is also exploring the idea that these reconnection events are likely a secondary process, which means that the particles that form the ribbon were not produced directly by the solar wind surge but from something else.
It collects data
IBEX collects data by scanning the outer edge of the solar wind, the high-speed stream of energetic particles from the Sun. It has two sensors that look at Energetic Neutral Atoms, or ENAs, a type of particle with no charge.
The IBEX team has used its observations to create a map of the Solar System’s heliosphere. The heliosphere is a bubble that separates our Solar System from interstellar space. It protects the Earth and other planets from the extreme heat and radiation of the Sun.
It also slows the flow of the solar wind. The heliosphere’s magnetic field lines trap the neutral hydrogen ions produced by the sun’s charged particles and strip away their electrons. This causes the ions to spiral around the magnetic field lines and form a dense ribbon-like region known as the IBEX ribbon.
IBEX’s measurements of the ribbon can help scientists figure out where the heliosphere is most likely to experience changes in the speed of the solar wind. This information can help researchers predict whether or not solar storms will disrupt the heliosphere, which is important for determining the health of our planet and its climate.
During the second and third years of IBEX’s observation, the heliosphere changed much more quickly than scientists expected. This rapid change, and a ribbon-like feature at the heliosphere’s nose that grew and faded over time, are challenging researchers to understand how such changes occur.
These changes may be influenced by differences in density and magnetic fields in the interstellar medium, which surrounds our Solar System. IBEX data is helping scientists to better understand the interaction between the solar wind and the interstellar medium.
This information can also help scientists study how particles are heated and accelerated in the heliosphere. IBEX is the first mission to measure these interactions at a distance.
The data from IBEX can also reveal how different regions of the heliosphere are affected by differences in density and magnetic fields. It will provide researchers with an understanding of how these differences impact the heliosphere’s structure, which can then help them determine how and why the heliosphere is changing so rapidly.
