From modern science, we have now realized that everything has to be “just right” for life to exist on Earth. Not only does our Earth need to be located in a narrow “habitable zone” of the Solar System, our Solar System also needs to be located in the “habitable zone” of our galaxy—the Milky Way. Heavy elements essential for life on Earth are insufficient if the Solar System is located too far from the center of our galaxy. The stellar environments are too hostile if we are located closer to the center of our Milky Way—a black hole.

Our Sun supplies us with energies mostly in the forms of heat and light. However, the nuclear reactions of the Sun also simultaneously emit large amounts of radiations that can damage all biological cells and destroy genetic codes in the DNA. For the most part, these radiations are harmful to life. To protect life on Earth, all of the electromagnetic radiations—which are more energetic than ultraviolet light and x-rays—are absorbed by the Earth’s atmosphere.

The magnetic field of the Earth also deflects solar winds and low-energycharged particles away from the lower atmosphere. Near the Earth’s magnetic poles, the Sun is never high up in the sky; therefore, the magnetic field lines of the Earth are never directly parallel to the direction of the Sun. The Earth’s magnetic field is still effective in deflecting solar winds, so that all we see near the poles is the corona lights (polar lights) caused by solar winds from the upper atmosphere.

However, because of the limited strength of the Earth’s magnetic field, energetic charged particles (cosmic rays) can still penetrate to the Earth’s surface. On average, the Earth is typically hit by about one cosmic charged particle per square centimeter per second. Since we are accustomed to this level of radiation, we have never been too concerned. Some people have considered this a “safe level” of radiation—but strictly speaking, “no radiation is safe radiation.” For medical diagnostic purposes or for cancer treatment, there may be some benefit in using radiation. However, the guiding principle for using radiation has always been “As Low As Reasonably Achievable” (ALARA).

The Earth’s magnetic field also preserves the Earth’s atmosphere from being carried away by solar winds. Our neighboring planet, Mars, is lacking a magnetic field like Earth’s. It has lost most of its atmosphere because of the direct impact of solar winds. The atmospheric pressure on the surface of Mars is now only 0.6% of our Earth’s atmosphere. The surface of Mars is therefore neither protected from radiation nor from showers of meteorites. It is definitely not a habitable planet like our home—Earth!

Today, we know that the center of our Milky Way is a black hole. It is unimaginably hostile to life. Our Milky Way is a disk-shaped, spiraling galaxy, and our Solar System is located about one-half to two-thirds of the radius out from the center and near the main plane of our galaxy disk. Extremely violent radiation jets are constantly shooting out from the center black hole and are perpendicular to the spiral disk plane. These intense jets are therefore not aiming at the direction of our Solar System and our Earth. However, supernovas from our galaxy and from other nearby galaxies are constantly emitting high-energy particles and are shooting in all directions. In space, these radiations and particles can be very damaging to biological cells.

Just a few months ago—on September 12, 2013—NASA announced that when Voyager 1 was exiting the Heliosphere on August 25, 2012, it measured a sudden increase of plasma density of about 40 times. This plasma sphere—a “stagnation region”—forms a “Heliosheath” starting at around 113 AU. (One AU is one unit of the distance between the Earth and the Sun, or 150 million kilometers. It takes eight minutes for light to travel across one AU.) Voyager 1 data showed that the solar wind dropped to zero outside of this plasma sphere—Heliopause—about 121 AU away. Also, right outside of this region—outside of the inner heliospheric current sheet between the Sun and this sphere—the magnetic field intensity is doubled, and high-energy particles detected in the interstellar space are 100 times more intense.

The Jet Propulsion Laboratory (JPL) of NASA operated the Voyager 1 space probe. It lifted off from Cape Canaveral in Florida on September 5, 1997. After flying by Jupiter in 1979 and Saturn in 1980, it picked up more speed using the “gravity assist” of Jupiter and Saturn. Since then, it has been on an extended mission, speeding to the outskirts of our Solar System. Voyager 1 has no solar panels. An onboard 470 watt radioisotope thermoelectric generator with a halflife of 87.7 years powers it. Its largest feature is a 3.7-meter diameter high gain satellite antenna disk. It carries a large collection of scientific measuring equipment—including radiation detectors, particle detectors, magnetometers, spectrometers, a plasma wave system, etc. Today, after 37 years—and at a distance of more than 127 times the distance from Earth to the Sun—the intensity of sunlight there is 15,000 times weaker than here on Earth. Many of its electronics (1977 technologies) are still functional. It takes 16 hours for radio signals to travel from Voyager 1 back to Earth. The Voyager 1 probe has made history as the first man-made object to enter interstellar space. Nevertheless, Voyager 1 is still capable of communicating with the Earth station, and is making discoveries and sending back interesting data.

The latest new discovery from Voyager 1 is really eye-opening! It reveals the existence of this protective sphere that is 113 AU to 121 AU away from the Sun. It is actively formed and maintained constantly by solar winds. This protective sphere is essential to all life on Earth! All of the harmful influx of charged particles coming from all directions of interstellar space are first attenuated by 100 times before entering into the inner part of our Solar System. The radiation level we are now “accustomed” to is only the remaining one percent of the harmful cosmic radiation that penetrates this protective sphere. Some of this radiation is further diverted by the Earth’s own magnetic field—converted into lower energy particles and/or absorbed by the Earth’s atmosphere. We who live on Earth have been doubly protected from all kinds of harmful cosmic and space radiations, and this was unknown to us until the discovery from Voyager 1 last year.

What can I say! The more we learn from modern science and technology, the more we can appreciate that our biosphere has been wonderfully and thoughtfully constructed to support life on Earth. How amazing is the grace of our Creator God!

“The heavens declare the glory of God; the skies proclaim the work of his hands” (Psalm 19:1).

“For since the creation of the world, God’s invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that people are without excuse” (Romans 1:20).

Denny Lee, Ph.D. in Physics, has been a research scientist in medical imaging—holding 33 US Patents—and is still currently active in particle physics research.