Wilkinson Microwave Anisotropy Probe

A special tool flies in space.

It looks at the sky. It finds heat from a long time ago. This heat is left over from when the world began.

The tool helps us learn many things. It shows us what the sky is made of. It even helps us find the age of the world.

This tool was very good at its job. It worked for nine years. It made a map of the whole sky.

It is a very big discovery!

The WMAP spacecraft was a special tool sent into space.

It flew from 2001 to 2010. Its job was to study the sky. It looked for heat left over from the Big Bang. This heat is called the cosmic microwave background.

WMAP helped us learn how the universe works. It found that the universe is 13.8 billion years old. It also studied what the universe is made of. Scientists found dark energy and dark matter in the sky. Dark matter is a thing that does not give off light.

The tool used five different radio bands to see clearly. This helped it ignore noise from our own galaxy. It made a very detailed map of the whole sky. This work won many big awards. It helped create a new model for our universe. The data from WMAP is still used by scientists today.

The Wilkinson Microwave Anisotropy Probe, or WMAP, was a very important NASA spacecraft.

Its main job was to study the cosmic microwave background. This is the leftover heat from the Big Bang. By looking at this heat, scientists can learn about the early universe. WMAP helped create the Standard Model of Cosmology. This model helps us understand how everything in space works.

To do its work, WMAP used a clever way to see. It used two large mirrors that faced in opposite directions. These mirrors helped focus signals onto special receivers. The spacecraft looked at the sky using five different radio frequency bands. These bands helped the tool ignore bright noise from our own Milky Way galaxy.

It measured the tiny temperature differences across the whole sky. This allowed it to make a very detailed map of the universe.

This mission had a long and successful history. It was originally called the Microwave Anisotropy Probe. In 2003, it was renamed WMAP to honor David Todd Wilkinson. He was a scientist who helped with the mission. The spacecraft launched from Florida on 30 June 2001. It was led by Professor Charles L. Bennett from Johns Hopkins University.

The mission lasted for nine years before it was turned off in 2010.

WMAP provided us with many amazing numbers and facts. It helped find that the universe is 13.8 billion years old. This measurement was accurate to better than 1% precision. The data showed that the universe is mostly made of dark energy and cold dark matter. Cold dark matter is a thing that does not emit or absorb light.

It also found evidence for a cosmic neutrino background in 2008. These facts changed how we see the entire cosmos.

Many people have celebrated the work of the WMAP team. Science magazine named WMAP the Breakthrough of the Year in 2003. The team also won the 2010 Shaw Prize in astronomy. They later received the 2018 Breakthrough Prize in Fundamental Physics. These awards show how much this mission helped science. You can think of WMAP as a giant cosmic camera. It took a picture of the very beginning of time.

The Wilkinson Microwave Anisotropy Probe, known as WMAP, was a landmark NASA spacecraft.

Its primary mission was to measure temperature differences in the cosmic microwave background (CMB). The CMB is the radiant heat left over from the Big Bang. By mapping these tiny temperature fluctuations, or anisotropies, scientists could study the universe's geometry and evolution. This mission was essential for establishing the Lambda-CDM model. This is the current Standard Model of Cosmology. It describes a universe dominated by dark energy and cold dark matter.

To capture this ancient heat, WMAP used a sophisticated system of mirrors and receivers. The spacecraft featured two large Gregorian dishes facing in opposite directions. These primary mirrors focused signals onto secondary reflecting mirrors. These signals then traveled to corrugated feedhorns located on a focal plane array box. The instrument used pseudo-correlation differential radiometers to measure the difference between two telescope beams. To ensure accuracy, the system used five discrete radio frequency bands from 23 GHz to 94 GHz.

These specific frequencies allowed the team to identify and subtract foreground signals. These signals come from our own Milky Way galaxy, such as synchrotron radiation and astrophysical dust. By removing this local noise, WMAP could see the true background of the universe.

Precision was vital for the success of the mission. WMAP was 45 times more sensitive than its predecessor, the COBE satellite. It also had 33 times the angular resolution of COBE. To keep the instruments stable, WMAP operated at the Sun-Earth Lagrange point 2 (L2). This location is about 1.5 million kilometers from Earth. L2 provides a thermally stable environment and minimizes interference from the Sun, Earth, and Moon. The spacecraft maintained its position using three reaction wheels, gyroscopes, and two star trackers. It also used eight hydrazine thrusters for steering.

The history of the mission began with a proposal in 1995. It was selected for study in 1996 and approved for development in 1997. The mission was a partnership between the NASA Goddard Space Flight Center and Princeton University. It was led by Professor Charles L. Bennett of Johns Hopkins University. WMAP launched from Florida on 30 June 2001. Originally, the mission was called the Microwave Anisotropy Probe (MAP). In 2003, it was renamed WMAP to honor David Todd Wilkinson. He was a cosmologist and a member of the mission's science team.

WMAP provided incredibly precise measurements about the nature of our cosmos. It determined that the universe is 13.8 billion years old. This measurement was accurate to better than 1% precision. The data also helped define the universe's contents. WMAP found that the universe consists of ordinary baryonic matter, cold dark matter, and dark energy. Cold dark matter is a substance that neither emits nor absorbs light. In 2008, the mission found evidence for a cosmic neutrino background. This discovery suggested an effective number of neutrino species of 3.046.

The mission's impact on the scientific community was massive. In 2003, Science magazine named WMAP the Breakthrough of the Year. Its research papers were among the most highly referenced in the history of physics and astronomy. The team received many prestigious honors for their work. They won the 2010 Shaw Prize in astronomy and the 2012 Gruber Prize in cosmology. In 2018, the team was awarded the Breakthrough Prize in Fundamental Physics. These awards recognize how WMAP changed our understanding of the Big Bang and cosmic inflation.

Even after the mission ended, the data remained valuable. WMAP was switched off in 2010 after nine years of operation. This followed the 2009 launch of the more advanced Planck spacecraft by the European Space Agency. WMAP's final official data release occurred in 2012. Scientists still study the WMAP data to look for unusual features. For example, they have studied a large "cold spot" in the data. Some measurements, like the quadrupole moment, appear slightly different than the Standard Model predicts. These small discrepancies continue to drive research into the mysteries of our universe.