Shop Windows to the Universe

Earth Science Rocks! Select one of our four cool NESTA t-shirts from our online store, and express your love of Earth and space science!
Neutrinos produced in the Sun have different energies. Different types of detectors are sensitive to different energy ranges.
Image courtesy of John Bahcall, Institute of Advanced Studies

The Solar Neutrino Problem

Theories about fusion inside the solar core predict the number of neutrinos that should reach Earth. Experiments on Earth have been set up to detect solar neutrinos in order to test these models. Current measurements show less neutrinos than the number predicted.

The first solar neutrino experiment was performed at the Homestake mine in South Dakota. A 600-ton chlorine fluid detector was used. It found a neutrino count about one third of that predicted.

The experiment at Kamioka, Japan, found about half of the predicted neutrinos. Recent experiments in Russia (SAGE) and Italy (GALLEX) use Gallium to detect neutrinos and have found neutrino fluxes up to 70% of the predicted flux.

Scientists are still trying to find out why their actual counts don't match up with the number of neutrinos that are predicted to come from the Sun.

Shop Windows to the Universe Science Store!

Cool It! is the new card game from the Union of Concerned Scientists that teaches kids about the choices we have when it comes to climate change—and how policy and technology decisions made today will matter. Cool It! is available in our online store.

Windows to the Universe Community

News

Opportunities

You might also be interested in:

Fusion Inside the Stars

Fusion in the core of stars is reached when the density and temperature are high enough. There are different fusion cycles that occur in different phases of the life of a star. These different cycles make...more

Neutrino detectors

Neutrino interactions with matter are extremely rare, so detecting a neutrino is very hard. Neutrino detectors are typically large, underground tanks filled with a fluid that reacts to the passage of neutrinos....more

The Cherenkov Effect

The theory of relativity states that no particle can travel at the speed of light in a vacuum. However, light travels at lower speeds in dense media, like water. A particle traveling in water must have...more

The Super Kamiokande

Super-Kamiokande is a neutrino detector located in the Kamioka Mozumi mine in Japan. Water fills this huge tank. In fact, it is the world's largest underground neutrino detector experiment (built under...more

IMF

IMF stands for Interplanetary Magnetic Field. It is another name for the Sun's magnetic field. The Sun's magnetic field is huge! It goes beyond any of the planets. The Sun's magnetic field got its name...more

The Hydrogen Fusion Process

In the basic Hydrogen fusion cycle, four Hydrogen nuclei (protons) come together to make a Helium nucleus. This is the simple version of the story. There are actually electrons, neutrinos and photons involved...more

The Neutron Capture Process

Neutron capture can occur when a neutron approaches a nucleus close enough for nuclear forces to be effective. The neutron is captured and forms a heavier isotope of the capturing element. When the new...more

The Supernova

A Supernova is a very massive star that explodes at the end of its life cycle. The supernova is the furnace where the heavy elements (heavier than iron) are formed. ...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF