The Parker Solar Probe approaches the sun in this artist’s depiction. The probe’s path takes it nearer to the sun than any other human-made object, allowing it to make close-up observations of solar activity.
NASA

The Parker Solar Probe has done the unthinkable. It became the first spacecraft to touch the sun! Scientists reported the announcement on Dec. 14, 2021, at the press conference at the 2021 American Geophysical Union Fall Meeting in New Orleans, Louisiana. The probe was built and operated by the Johns Hopkins Applied Physics Laboratory. The probe flew through the upper atmosphere of the sun, called the corona, to collect samples. The samples will allow scientists to understand more about the sun, just like landing on the moon paved the way for scientists to learn about the moon.

The National Aeronautics and Space Administration (NASA) launched the Parker Solar Probe in 2018. The probe completed its first orbit of the sun in 2019. The probe is the fastest human-made object in the solar system. The sun’s gravity is expected to accelerate the probe to extreme speeds of up to 430,000 miles (700,000 kilometers) per hour. Three years after the launch, the probe has arrived at the sun.

The goals of the mission are 1) to study how energy and heat flow through the corona; 2) to gather information on plasma (the gaslike substance the sun is composed of) and magnetic fields near the sun; and 3) to learn more about how high-energy particles travel outward from the sun.

It uses a set of instruments known as FIELDS, which has antennas to measure electric fields and magnetometers to measure magnetic fields. The probe is also equipped with a pair of cameras to capture images of the sun. The probe carries various instruments for studying particles in the solar wind—that is, the continuous flow of particles from the sun.

The sun’s corona can be as hot as 4,000,000 °F (2,200,000 °C). Because of the corona’s low density (concentration of matter), the Parker Solar Probe will not experience the sun’s most intense heat. However, it will encounter temperatures of up to 2,500 °F (1,377 °C)—hotter than lava from a volcano.

The Parker probe is planned to approach the sun 24 times by the mission’s end. Hopefully, the Parker probe can stand the heat and gather more information about the corona and solar winds.

March 13, 2014

Four new chemicals that are almost certainly human made are threatening the recovery of the protective ozone layer in Earth’s upper atmosphere, according to scientists from the University of East Anglia in the United Kingdom. The origin of the gases, which were not in the atmosphere before the 1960′s, is unclear, but they appear to be coming from somewhere in the Northern Hemisphere. Even more worrisome, emissions of two of the gases seem to have risen in recent years.

Ozone is a gas that is present in small amounts in Earth’s atmosphere. In the troposphere (the lowest level of the atmosphere), ozone is a pollutant. However, in the stratosphere (the layer above the troposphere), ozone blocks harmful ultraviolet rays from the sun, protecting life on Earth.

In the 1970′s, scientists monitoring the atmosphere over Antarctica noticed that the ozone layer was becoming depleted (less concentrated) each spring. This area became known as the ozone hole. In 1985, researchers discovered that the ozone hole had grown since the 1960′s. That is, over the years, the area of low concentrations of ozone had become larger. In addition, the ozone concentrations had become smaller. Scientists soon linked the ozone hole to chemicals called chlorofluorocarbons (CFC’s). CFV’s were once widely used as refrigerants and as propellants in aerosol spray cans. The international community acted quickly to protect the ozone layer. In 2010, a total global ban on CFC production went into effect. But an ozone hole still occurs every year because of CFC molecules that remain in the atmosphere. Although atmospheric concentrations of ozone-damaging chemicals have fallen in recent years, the ozone hole was not expected to heal completely until at least 2050.

A false-color view shows the total ozone over the Antarctic pole on March 7, 2014. The purple and blue colors are where there is the least ozone, and the yellows and reds show where there is more ozone. (NASA/Goodard Flight Center)

Three of the newly discovered chemicals in the ozone layer are CFC’s. The fourth is a hydrochlorofluorocarbon (HCFC), which also damages atmospheric ozone. The British scientists reported that 82,000 short tons (74,000 tonnes) of the gases have been released into the atmosphere so far. Analyses of old, compact snow, known as firn, and modern air samples revealed that the gases have appeared in the past 40 to 50 years.

The scientists speculated that the new chemicals could be appearing because of loopholes in the Montreal Protocol, which banned most CFC’s. The treaty allows the use of extremely small amounts of CFC’s in the manufacture of certain insecticides and in solvents used to clean electronic equipment. However, the gas emissions could also be the result of illegal production. The scientists called on governments to identify the source of the gases so production can be halted immediately.

Additional World Book articles:

• Air pollution
• Greenhouse effect
• Rowland, Frank Sherwood
• Smog
• Environmental pollution (1988) (a Back in Time article)
• Environmental pollution (1990) (a Back in Time article)

Dec. 6, 2011

The amount of heat-trapping carbon dioxide (CO₂) being pumped into Earth’s atmosphere jumped to record levels in 2010, according to the annual report by the Global Carbon Project (GCP). The GCP is an international collaboration of scientific organizations. The report said that the emissions rose by 5.9 percent, more than one-half billion tons of carbon. It was the largest annual increase since scientists began taking precise measurements of CO₂ emissions in 1959.

The disappearance of sea ice poses a threat to the wildlife of the Arctic Ocean. These satellite photographs show the extent of summer sea ice in 1979 (left) and 2005 (right). The ice covering has decreased as a result of global warming, an increase in the average temperature at Earth's surface. NASA

GCP scientists also calculated that the 2010 rate was almost certainly the largest yearly jump since the beginning of the Industrial Revolution in 1750. Based on these numbers, the scientists calculated that the concentration of CO₂ in the atmosphere has reached its highest level in the past 800,000 years. CO₂ emissions had dropped slightly in 2009 because the worldwide financial crisis had reduced manufacturing. The GCP scientists calculated that about half of the emissions remained in the atmosphere. The rest was absorbed by the ocean and bodies of water on land as part of the carbon cycle.

Other highlights of the report included the following:

• China, India, and the United States led the world in CO₂ emissions in 2010;
• China accounted for 24.6 percent of total emissions, compared with 16.4 percent for the United States;
• A large percentage of the emissions came from the burning of fossil fuels in power plants and factories and the production of cement;
• Annual CO₂ emissions from burning fossil fuels have increased by 49 percent since 1990, the base year used by the Kyoto Protocol for calculating reductions.

Additional World Book articles:

• Global warming
• The Great Meltdown (a Special Report)
• The Ocean’s Changing Chemistry: Tipping the Balance? (a Special Report)