In a surprising turn of events, Voyager 1, after decades of exploring deep space, has established contact with an unknown force in interstellar space.
The Voyager mission began in 1977 with the launch of two
space probes: Voyager 2 on August 20 and Voyager 1 on September 5. Although
launched later, Voyager 1 traveled faster and reached its destination first.
Both missions were intended to explore Jupiter and Saturn, providing detailed
information about these gas giants, their moons, and other elements of space.
Discoveries in Interstellar Space
Voyager 1 is currently the most distant human-made object,
transmitting data from more than 22.7 billion kilometers from Earth. This data has
revealed that interstellar space is not empty as previously thought but rather
contains a constant presence of plasma.
One of the most important findings is a persistent,
low-frequency hum, recorded at approximately three kilohertz. This phenomenon
demonstrates the existence of plasma, a form of matter in which electrons have
been stripped from atoms due to its high temperature.
The Presence of Plasma in Interstellar Space
Voyager 1 had previously detected plasma disturbances caused
by ejections from the Sun's corona. However, for the past three years, the
spacecraft has recorded a continued presence of plasma at lower levels,
suggesting that this material is abundant even far from the Sun's influence.
Scientists have determined that the plasma detected by Voyager 1 extends at least 1.5 billion kilometers , based on the spacecraft's speed of 61,000 kilometers per hour . However, unanswered questions remain:
- What is the origin of this plasma if it does not come from the Sun?
- Why wasn't it detected earlier if Voyager 1 had already been in interstellar space for years?
Voyager 2 and Its Discoveries
In 2018, Voyager 2 became the second spacecraft to reach interstellar space, six years after Voyager 1. Its instruments confirmed dramatic changes in energetic particles:
- A drop in the amount of heliospheric particles was detected.
- The presence of cosmic rays increased significantly.
Another key discovery was that the magnetic field in the
heliopause (the transition region between the heliosphere and interstellar
space) is completely parallel to the magnetic field of the heliosphere.
Although Voyager 1 had already observed this phenomenon, Voyager 2 confirmed
it, raising new questions about its origin.
Plasma Temperature and Density Differences
A surprising finding of Voyager 2 was the difference in temperature and density of the plasma in both regions:
- In the heliosphere, the plasma is hotter than previously thought and experiences a temperature increase before entering interstellar space.
- In interstellar space, plasma is colder but denser, which contradicts scientific expectations.
These variations continue to be a mystery and an object of
study for astronomers.
Exploration of Uranus and Neptune
Voyager 2, in addition to studying Jupiter and Saturn, was the only spacecraft to approach Uranus and Neptune.
- Uranus (1986): Ten new moons, several unknown rings , and a deformed surface were discovered on the moon Miranda, suggesting that it may have broken up and reformed. Furthermore, extremely cold temperatures were recorded, as low as -214°C, making it the coldest planet in the Solar System.
- Neptune (1989): Voyager 2 discovered six new moons, four rings, and the Great Dark Spot, a huge storm caused by strong gusts of wind.
The Voyager Legacy
The Voyager probes have revolutionized our understanding of
the solar system and interstellar space. Despite their age, both continue to
return valuable data and are expected to continue operating for several more
years, providing crucial insights into the mysteries of the universe.