We study both Jupiter and solar radio emissions to better understand
their magnetic fields and their plasma [charged particle] environment.
Studying other planets always helps us better understand the Earth, and
this is true when we study Jupiter's radio emission. Earth also emits
radio waves by similar processes, so we can better understand this process
by listening to Jupiter from both ground-based and space-based radio
Not only can we learn about why the radio waves are created and how
they move through space, we can also learn about the interior of Jupiter
and about Jupiter's moons. Radio waves are generated because the planet
has a magnetic field. This magnetic field originates deep in the interior
of the planet, and the overall strength of the magnetic field directly
affects the type of radio emission emitted by the planet. This helps us
with the theory of how the magnetic field is created in the interior, and
in determining the composition of the various interior layers.
Jupiter's moons are close enough to Jupiter that they interact
electrically and magnetically with Jupiter's magnetic field. The moon Io
directly influences the radio emission, so we can learn about Io as well.
Recently it was discovered that some of the other large satellites are
influencing the radio emission, so we are now learning more about their
composition and magnetic properties.
By studying radio emissions from the Sun we can similarly learn about
the magnetic field of the Sun. We cannot make direct inferences about
Earth by studying the Sun, but we can better learn how our Sun works and
thus how all other stars work. Studying radio emission also helps
scientists learn about the 11-year solar cycle, because the amount and
types of radio waves that are emitted change with the solar cycle.
Another crucial reason we study radio emission from the Sun is to
better understand how the Sun affects the Earth. The solar wind directly
impacts Earth by influencing our magnetic field and our space environment. The solar wind causes aurora and can also affect communications, our power grids, and even our astronauts out in space. We want to understand the
connection between the Earth and the Sun so we can learn more about each
body and more about how humans are affected by this interaction.
Jupiter produces a wide range of bursts with different sounds. The two
most common types are L-bursts and S-bursts. L-bursts (long bursts) last
from a few tenths of a second to a few seconds and sound like ocean waves
breaking up on a beach. S-bursts (short bursts) have durations of a few
thousandths to a few hundredths of a second and can occur at rates of tens
of bursts per second. Groups of S-bursts sound like popcorn popping - or
like a handful of pebbles thrown onto a tin roof. S-bursts are often
associated with the Io-B or Io-C source. Many times the Jovian activity is
a mix of L and S-bursts, making the sounds a little more difficult to
identify. Jovian activity extends over at least a few hundred kiloHertz so
if you suspect that you are hearing Jupiter bursts tune the radio slightly
- if the signals persist then it is most likely Jupiter and not a station fading in and out.
Solar bursts typically last from half a minute to a couple of minutes
and often sound like a rapid increase in the background noise followed by a gradual decrease back to the original baseline level.
You can hear recorded Jovian bursts at the University of Florida Web
, and Solar and Jovian bursts at the Windward Community College Hawaii Web
as well as on the JOVE Web site at http://radiojove.gsfc.nasa.gov/data_analysis/data_samples.htm.
Please see the answer to the previous question.
Experience will make the sounds of Jupiter familiar and easier to
identify. Listen carefully to the recordings of sample Jovian bursts
several times. How would you describe those sounds? It may be helpful to
listen to the various sounds picked up by your Radio JOVE receiver at
times when you don't expect to hear Jupiter. Local machinery, electrical
equipment, and atmospheric conditions produce a host of different sounding
noise. The PC that you use may also make some noise that can be picked up
by your receiver (the CRT monitor is a common source). Become familiar
with these non-Jovian sounds, and you'll be able to distinguish Jupiter's
decametric radio emissions.
We suggest that you listen carefully to the bursts as an aid to
identification. Solar bursts sound like you had turned up and down the
volume control - in other words the sound (character) of the noise is the
same - it just gets louder during a solar burst.
Interference on the other hand has a different sound - power line
arcing for instance has a raspy buzzing sound. During the daytime you may
also be picking up station interference - you should of course tune the
receiver to a clear frequency. Sometimes distant stations will fade in and
out - making it a bit more difficult to find a good clear frequency.
Abrupt turn on and turn off of noise suggests that it is manmade - for
example rotary machinery like an electric drill can generate radio noise.
So can light dimmers, aquarium heaters, electric fences, electric blanket
thermostats, automobile ignition systems, computers and just about a
million other electrical appliances. But with a little practice you will
learn to identify the pure sounding noise associated with a solar
An order form for the Radio JOVE radio telescope kit can be found on
our Web site by going to the Radio JOVE home page and clicking on the Order Form link.
Follow the instructions on that form.
Yes! While our project is intended to make planetary radio astronomy an
educational experience for students, many amateur scientists have joined
Radio JOVE. Please fill in and submit an observing team application form
with the information that applies to your situation. This will enable us
to share information from the project and from other observers with
Many Radio JOVE participants share their interest in the project with
scouts and individual students from their areas. Maybe there are some kids
from your neigborhood, or local scout troops who would enjoy learning
about Radio JOVE? Why not invite them to observe with you?
Several authors have contributed sophisticated programs suitable for
use by Radio JOVE. These programs include functions such as chart
recorder-type intensity plots, data logging, observing aids, audio
spectrum displays, and even multi-observer data sharing.
You can find these programs by going to the Radio JOVE home page and
clicking on the Data Analysis Lab link. From there, select the Useful
Software link. Or enter http://radiojove.gsfc.nasa.gov/software/
in the location box of your web browser.
Please remember that you are bound by the license agreements for the
software that you install and use.
Your first course of action should be to re-read the construction
manual carefully - especially the section on troubleshooting. The Radio
JOVE project maintains an e-mail distribution list. This is useful for
asking questions about any problems you encounter. If you've provided a contact e-mail address on your team application, you should have been added to our e-mail list.
Additional information can be found on our Radio Telescope page under
"Testing Receiver & Antenna".
If you require hands-on assistance, you might find an electronics
hobbyist or an amateur radio operator in your area who is experienced at
building and trouble-shooting electronic circuits. See our Web page "Teaming with
Radio Amateurs" for information on seeking help from ham radio
operators or amateur radio astronomers.
When you tune in a broadcast or shortwave station on your radio you
find that the signal occupies only a small region of the radio dial. I
could tell you to tune in WWV on 20 MHz, for example, and you would find
the signal right there at 20 MHz. Just above and below 20 MHz, the signal
from WWV would be absent. This is because radio stations are narrow band
transmitters. Any one station occupies only a small chunk of the
Most non-artificial transmitters of radio waves, like the Sun and
Jupiter, send out emissions over broad segments of the electromagnetic
spectrum. In fact, they tend to emit at least some energy at every
frequency in the entire spectrum, though not evenly. The Sun and Jupiter
have complex emission mechanisms that produce signals which may be quite
strong over a range of frequencies, usually many MegaHertz wide. These
broad emissions can drift, (usually downward), in frequency in a matter of
seconds, so they can be moving targets. The answer to the question is that
there is no one frequency where you tune in to find Jupiter or the Sun.
You can tune your receiver around a bit to avoid interference but as far
as the signals from Jupiter or the Sun are concerned, it will make no
difference if you list at 20.10 or 20.150 MHz, for example. If you hear
one of these sources at one of these frequencies, you will hear at the
Having said all this, you should understand that there are some ranges
of frequencies that are better for listening for these signals. Below
about 18 MHz, it is very hard to pick up signals originating from space
because the Earth's ionosphere absorbs and reflects the signals at these
lower frequencies. Above about 40 MHz, Jupiter does not produce noise
storm signals. Solar bursts are best heard from about 200 MHz and downward
to the 18 MHz band. Not all solar bursts cover this entire range and
sometimes a burst will be heard at 50 MHz, for example, but not be heard
at all 20 MHz.
Jupiter emits radio waves that can be detected here on Earth, but it is
not continuous emission. These bursty radio emissions depend directly on
the space environment around Jupiter. Fortunately some of these radio
emissions are predictable because they depend on the position of the moon
Io in its orbit around Jupiter. Knowing the correct longitude of Jupiter
and the position of Io, we can make prediction tables that help you know
when to observe Jupiter. These predictions are not perfect, but they give
you the best opportunity to detect the radio storms.
To check the prediction tables you can go to three sources:
University of Florida's Radio Observatory Prediction Tables
2. Astronomer Jim Sky from
Radio JOVE has prediction reports:
3. Get the listing from our Radio
Now you have made an observation. What can you do with your data? First
if you have made a tape recording of it, you can make a digital computer
file by playing your tape recording into your computer via your sound
card. This allows you to plot the data on an intensity versus time graph
using the available software with your kit (Radio Jupiter Pro, or
Skypipe). You can then do many things:
1. Compare your observations with others by looking at data archives on
Submit your data for our Radio JOVE archive
3. If your data is a solar
burst, check the NOAA website to see if they observed the same radio
4. Use the Radio
JOVE Classroom page to look at Lesson Plans on how you can make
interesting calculations with your data.
[ For additional information on this topic, please see our Projects and Experiments page. ]
If you are observing Jupiter, there are a number of questions about
how consistent the patterns of emission are for a particular source.
Of course, one obvious experiment is to see how well the predictions
of storm probability match the actual occurrence of storms. The
storms are not usually continuous, however. When listening to
Jupiter on a particular night you will find that the Jupiter storms
often occur in a periodic fashion, maybe on the order of every 5-15
minutes. The patterns of this emission will depend on the "storm
track" through the high probability area of the radio sources as
depicted by the CML-Io Phase plot in the Radio Jupiter Pro software.
These periodicities give us information about how the storms are
generated and "beamed" to us and we would like to know if they are
consistent or vary with time. Thus, it helps to have multiple
observations of a particular source with the same "storm track". We
encourage observers to make these observations and submit their data
to our archive and then compare to other observations of the same
storm or other past observations of a similar storm track.
If others are including calibration signals in their data, you can
use lesson 7 in the lesson plans on the CD or website to compute the
power of the Jupiter storm. (Hawaii and the University of Florida
regularly include calibration signals in the transmissions they send
out.) In doing these comparisons you may note some consistencies
such as the tendency of the Io-A source to start with an intense
emission whereas the Io-B source often ends with an intense emission.
There are other archives you can compare with, such as the one for
the decameter array observations in Nancay, France. This array
observes at multiple frequencies using a spectroscope so it gives
even more information about what is happening than the single
frequency Radio JOVE observations.
You might also consider comparing widely-scattered observations of
the same storm to see how they differ from one observer to another.
Solar storms often compare very well over a wide range of observers
since they are so strong, whereas Jupiter observations may differ
quite a bit for simultaneous observations since they are weaker and
more greatly affected by the Earth's intervening ionosphere acting
like a variable cloud layer between the observer and the source.
Thus, the variations give us information about the Earth's ionosphere
and how it varies from one place to another or from one time to
If you are observing the Sun, it is a much stronger source, but
generally unpredictable. We believe for both Jupiter and the Sun
that the emissions are generated by charged particles moving in
magnetic fields. Jupiter has a very regular and fixed magnetic field
whereas the Sun's is very dynamic and changeable. We can use the
radio observations to learn about the nature of the radio emission
sources that cause solar storms. For example, do you notice that
solar storms generally rise to a peak of emission faster than they
drop off afterward? What does that tell you about the source? What
are the durations of the storms? What is the minimum and the maximum
that might be expected? Jim Brown, director of the Stanback
Planetarium at South Carolina State University recorded multiple
years' worth of solar observations and has some interesting
statistics in this regard.
If you want to get into some of the more technical aspects of solar
radio storms look up information on Type II and Type III solar
storms, what they mean, how they might be seen by Radio JOVE, and
what might be going on at the Sun when they happen. How can your
data contribute to the knowledge of these storms?
You could also just study the nature of radio transmission in
general. How much interference do you get and how might that be
related to current weather, season of the year, time of day, etc?
When and when don't you get WWV signals? What might that be related
to? What kinds of interference do you hear and are distant stations
hearing the same interference? What might be the cause of such
The constant background "hiss" is related to what we call the
"galactic background", that is, the constant emission by charged
particles moving in the galactic magnetic field. If you have a way
of recording this over many hours in a very consistent way it is
possible to note a gradual rise and fall in this background level
related to whether the center of our galaxy is close to or far away
from the center of the radio beam.
So, in summary there are a number of project that can be done with
the data limited only by your imagination and willingness to dig a
little into previous research that has been done and expanding upon
it. Look at the references in the JOVE library area if you want
possible sources of other ideas. Remember that even failure to have
the data behave the way you would like or expect is telling you
something that you should track and try to explain so that others
might benefit from your experience. If you find that you are often
frustrated in the science you are trying to do then you know you are
doing real science. Happy observing!
Yes -- however, you must be able to turn off the automatic
gain control circuit (AGC). Many ham radio transceivers have an AGC mode switch
(slow, medium and fast), as well as AGC off. In the AGC off position the
receiver gain may be manually adjusted with the RF gain control. High gain
settings may limit the dynamic range of the receiver causing it to clip the
tops off strong bursts. The proper gain setting may take some experimentation.
If your transceiver
operates only in the ham bands then try either the 15 or 17 meter band for
Jupiter. Solar bursts may be stronger in the 10 meter band where ionospheric
attenuation is less. Of course you must use an antenna cut for the frequency of
operation. A ham antenna such as a Yagi, or a quad can be used when Jupiter or
the Sun is relatively close to the horizon.
A general coverage
shortwave receiver could operate with the JOVE antenna at 20.1 MHz. One of the
few new general coverage shortwave receivers with an AGC off switch is the ICOM
R-75. You can feed the receiver audio to your computer sound card and use Radio-SkyPipe
signal strength plotting software to record radio noise bursts.
No, your satellite dish was designed for microwave
reception. Although Jupiter emits weak signals in the microwave spectrum they
are not strong enough to be detected with a small dish. The radio Jove project
monitors Jupiter and the Sun at 20.1 MHz. At this frequency Jovian signals are
quite strong (and the Sun is even stronger). Most observers use the Jove dual
dipole array. Some use Yagi antennas. A single dipole antenna is sufficient
to pick up strong solar bursts.
An article published several years ago proclaimed that a
small loop antenna (about 5 ft diameter) known as the DDRR was suitable for
listening to Jupiter. Most seasoned observers doubt the claims made for this
antenna. As far as we know there has never been a good scientific comparison
made between the small loop antenna and full size antennas like the Jove dual
dipole array. To be useful, such a comparison would require side-by-side
operation with identical equipment using a common calibration source. While,
this might make a nice project for an advanced amateur scientist, it is not
suggested as your first project. We suggest you use the field proven JOVE dual
dipole antenna. Antenna experimentation is an exciting and fun activity and if
you are technologically savvy, feel free to give it a try. However, for the
beginning Jupiter observer, you will probably find that there is challenge
enough without adding another "unknown" factor into your experiments.
first thing to do is test the receiver and antenna hooked up together. Make
sure that you have a good radio quiet listening site. Learn how to connect
your receiver to a computer sound card and display signals using Radio-SkyPipe
Jupiter observations are carried out at night, usually at
specific times when radio noise storms are predicted. This web site posts
information on predicted storms. You can also use Radio Jupiter Pro 3 software to determine when to listen.
Jupiter and the Sun are being monitored by professional
radio observatories in Florida (UFRO) and Hawaii (WCCRO). These observatories
stream Radio-SkyPipe data and radio spectrograph displays as well as live audio
over the Internet. You can compare what you are receiving with your Jove
equipment with on-line signals from these professional observatories and other observers.
on observing Jupiter's emissions can be found in Richard Flagg's book
"Listening to Jupiter" which is included on your Radio JOVE CD-R and
available in hardcopy from RadioSky Publishing.
NO, it is not safe! One JOVE team member lost a receiver and
computer to a nearby lightning strike. ALWAYS disconnect your antenna if there
is a nearby lightning storm. The best practice is to disconnect your antenna
from the receiver when it is not in use.
noise bursts from the Sun can be very strong . a single dipole antenna should
be adequate. The Jove antenna kit contains materials for two dipoles, so for
the sun all you have to do is put up one. As for the height . the higher the
antenna, the closer to the horizon it will look. If the sun is passing close
to overhead at local (as it will in June and
July in the northern hemisphere) then mount the antenna at about 10 feet. If
you want to get the best performance in wintertime in the northern hemisphere
(when the sun is closer to the southern horizon) then you could raise the
dipole to 20 feet. However, you can still receive solar bursts with the dipole
at 10 feet year round.
If you have no clear open space on the ground to erect the antenna then
it may be worth trying it on a rooftop. The antenna pattern may be
affected by metal in the roof structure and roof mounted air conditioning
units may generate undesirable electrical noise. A rooftop antenna may
also be more susceptible to lightning and should always be disconnected
when not in use. (It is a good precaution to disconnect any antenna when
not in use - particularly during lightning season.)
Yes, you can. A cable run of up to 200 feet should be acceptable. Use 75 ohm coax such as RG-59 or RG-6 (or RG-6 quad shield). RG-6 is slightly lower loss. If you are going to use a longer feedline we recommend that you completely replace the one wavelength piece supplied with the kit - rather than splicing another length of cable onto the end. Be sure to use type F connectors that match the coax you select.
A well-regulated 120 volts AC to 12 volts DC power supply such as the 12VDC Regulated 500mA supply from Jameco is recommended (part number 162996). It sells for under $10. This power supply includes the proper power connector that plugs right into the RJ Receiver (no danger of hooking it up backwards). The price may vary depending if it is ordered by phone or over the Web.
Many power modules that plug directly into the wall (known affectionately as "wall warts") are poorly regulated and can cause severe hum problems when used with the JOVE receiver.
The gain of each Jove receiver is probably a bit different depending upon how precisely it is tuned up. Usually the receiver volume control should be set between the 12 o'clock and 3 o'clock position. Low volume settings give the receiver more "dynamic range" than high settings. A large dynamic range is desirable for strong bursts. Since solar bursts can be stronger than Jupiter, use the lower gain setting for solar observations. The 12 o'clock setting may also work fine for Jupiter. Once the receiver gain is set, adjust the software (recording) volume control in Windows so the background trace on Radio-SkyPipe is at approximately 1000 on the Radio-SkyPipe vertical scale
No, your radio is not broken, but it is being overloaded by a very strong shortwave transmitter. The frequencies in the range used by the Radio JOVE receiver are very actively used by man-made transmitters. These are especially noticeable during the daytime and may temporarily overload the receiver. Other observers have had this problem, which has been traced to Radio Marti broadcasting on 21.5 MHz. One solution is to use a filter designed to reject signals outside the tuning range of the JOVE receiver. For information on such a filter send e-mail to email@example.com .
You are hearing an ionosonde, which is used to probe the Earth's ionosphere. It transmits a signal that sweeps across the radio frequency spectrum. Each time it sweeps past 20.1 MHz it sounds like a chirp in the JOVE receiver. Ionosondes are operated all around the world by various government agencies and research groups.
The Radio shack #23-007 lantern battery will last on the order of 10
hours of powering the JOVE radio. The battery should be replaced if the
DC voltage drops below 10.5 volts. Measure the voltage across the
battery terminals with a DC voltmeter or a suitable multimeter.
(Make this measurement when the receiver is turned on.)
Longer life options include the Power Station -
a rechargeable 12 volt battery available at Radio
Shack and other outlets. Also, with a suitable fused adapter the JOVE
receiver can be powered from the cigarette lighter of a car. Note that
there is no fuse inside the JOVE receiver and to exercise caution not to
short out the power connection to a large battery! REMEMBER, ALWAYS
OBSERVE WITH SAFETY IN MIND!
If the Jove receiver does not tune up properly it is likely due to a poor solder connection or an incorrectly installed component
Look at every solder joint, using a magnifying glass and a bright light. Each joint should be shiny and the solder must flow smoothly around both the component lead and the solder pad. Resolder any suspicious joints. Look for solder bridges, particularly between adjacent IC pins. Solder bridges are easily removed using solder wick.
Using a DC voltmeter, check for proper voltages as seen in Figure 19 of the Jove receiver manual. Incorrect voltage readings can narrow down the problem area. This schematic shows 6.1 volts at the output of IC2, which is the correct for early versions of the receiver (using R14 = 100K ohms). Recent receiver kits have shipped with R14 = 33K ohms. For this value of R14, the output voltage of IC2 should be close to 3.1 volts.
Review the location of each component, paying particular attention to the orientation of the integrated circuits, transistors, diodes, and polarized electrolytic capacitors. If you need to remove a component use either solder wick or a solder sucker. Solder wick (Radio Shack Desoldering Braid 64-2090) is the least expensive method. The more expensive solder sucker (Radio Shack Vacuum Desoldering Tool 64-2098) is a plunger-activated device that works by sucking melted solder off the board.
If you are unable to get the receiver working you may contact any of the Jove team members or the receiver designer at firstname.lastname@example.org for additional assistance.