Watch the ISS Pass on 3 April - Cité de l'Espace

Watch the ISS Pass on 3 April

Watch the ISS Pass on 3 April

On 3 April, at 9 p.m., the International Space Station (ISS) will begin to pass over France under good conditions for observation. We will explain how you can enjoy it in complete safety.

ISS passes are far from rare, the orbiting complex going around our planet 16 times every day! But every pass is not the same, the station being higher or lower in the sky at a given location and the angle with the Sun not always being at its best (the ISS itself does not shine, it reflects the light of our star).

 

Friday 3 April 2020, looks good and that’s why we are giving you the details on how to observe this phenomenon by taking Toulouse (where Cité de l’espace is located), Bordeaux, Nantes, Paris, Lyon and Marseille as examples. If you don’t live in one of these cities, choose the nearest one, the parameters will be similar enough.

Respect Health Guidelines while Observing

During this time of fighting the SARS-CoV-2 coronavirus pandemic, we must, of course, and above all, comply with the health guidelines. So, don’t leave isolation to observe the ISS passing. Moreover, it’s not necessary.

Those who are isolating in a house with a private garden can use it to access an immense view of the sky. In an apartment, you can see the station from your balcony (without leaning over, thank you!) if it faces in the directions specified below. If you only have a window, you can check the direction it faces and be even more careful about not leaning out to see the pass as it nears its zenith. In the event you cannot observe the pass without putting yourself at risk, you can watch the “rise” of the ISS in the sky by looking in the right direction (again, we give you the details below). Even if you have no compass, don’t forget your smartphone if you have one: most come with an app for navigating which will help you choose your balcony or window.   Time is given in French local time.

Carte du passage de l’ISS au-dessus de la France le 3 avril. Crédit : Heavens-Above

Carte du passage de l’ISS au-dessus de la France le 3 avril.
Crédit : Heavens-Above

Some Examples of ISS Passes on 3 April

The phenomenon will therefore be visible across the whole of France, its vertical is over the Nantes region or the Lyon region (cf. map above). On Friday 3 April, look at this brilliant spot in the sky coming from the North-West at 9 p.m.. A bright clearly visible spot, which at that precise time will already be above the horizon. It will be moving quickly in the sky. Look up and your eyes alone should be enough to detect it. Please share your observation as many did on 24 March by posting to us on Twitter at @CiteEspace.

Now the details for Toulouse, Bordeaux, Nantes, Paris, Lyon and Marseille. Choose your nearest city for a good estimate of the conditions.

Update on 3 April: on 2 April, the ISS made an orbit correction. The changes to the 3 April pass are minimal (from a few seconds to one minute of difference), but we updated the maps and schedules.

Toulouse Pass

Look to the North-West, so to the right of Venus* (cf. map from the Heavens-Above site below) which will be the brightest star in the sky. The map also shows that the ISS will cross two fairly well-known constellations: first of all Cassiopeia (W shaped), then the classic Great Bear.

(*) Don’t forget that a sky map is designed as if you are looking at it overhead.

The ISS will rise from the North-West horizon and reach a height of 10° in the sky at 9.01 p.m. Its brilliance will increase to a magnitude of -3.3 (comparable to Venus) a few seconds before 9.04 p.m., at which time the station will be at its highest in the Toulouse sky at 52° in the North-East (basically to the North). It will then be 528 km from Toulouse (its orbital altitude is around 400 km, the difference is explained by the fact that it does not pass exactly above the city).

 

Reminder: magnitude is on a scale which indicates the brightness of a celestial body and the higher the number, the less visible it is. The visibility limit to the naked eye outside any light pollution is 6. The ISS on that evening will have a negative magnitude, so it will be one of the brightest “celestial bodies” in the sky, Venus and the Moon being its only “competitors”.

To summarise.

An altitude of 10° at 9.01 p.m. (to the North-West)

At 52° at its highest at 9.04 p.m. (to the North-North-East)

Enters the Earth’s shadow (at 12°) a few seconds after 9.07 p.m. (East-South-East)

 

Bordeaux Pass

Conditions are close to those for Toulouse and we also take a heading to the North-West, to the right of Venus. Here too, the ISS will cross the Cassiopeia and Great Bear constellations. As Bordeaux is further north, the ISS will “rise” a bit higher in the sky, as far as 57°. The magnitude will be -3.4, similar to that of Toulouse.

Below, the map of the pass in the sky, calculated by the Heavens-Above site.

To summarise.

10° of altitude a few seconds after 9 p.m. (to the North-West)

At 57° at its highest a few seconds before 9.04 p.m. (to the North-North-East)

Goes under 10° and returns to Earth’s shadow shortly after 9.07 p.m. (East-South-East)

 

Nantes Pass

Here the geometry is different, since in Nantes, the pass will almost take place at the Zenith (at 90°). The brilliant Venus will be a good marker and you should look a little to the right and below it. At its peak, the ISS will only be 426 km away from the people of Nantes, only a few kilometres more than its orbital altitude, which stands to reason given the geometry of the pass over the city.

Below, the map of the pass in the sky, calculated by the Heavens-Above site.

In Nantes, look for a clear view of the West-North-West horizon as well as a clear zenith, since the ISS will peak at 83°!

To summarise.

10° of altitude at 9 p.m. (to the West-North-West)

An altitude of 83° at 9.03 p.m. (more or less at the zenith)

Goes below 10° a few seconds before 9.07 p.m. (East-South-East)

 

Paris Pass

For the capital, the ISS will pass at a lower level than in Nantes and you will need a clear sky to the South.

Below, the map of the pass in the sky, calculated by the Heavens-Above site.

In Paris, the ISS will have a maximum magnitude of -3.4. Note that it will pass not far from Venus, which consequently makes it a very useful marker! The station will peak at 58°.

To summarise.

10° of altitude at 9 p.m. (to the West-North-West)

At 58° at its highest, a few seconds before 9.04 p.m. (to the South-South-West)

Goes below 10° a few seconds before 9.07 p.m. (South-East)

 

Lyon Pass

We leave the north, going further south. The ISS will pass close to the zenith in this area. We start by looking to the West-North-West to the right of, and a little below, Venus.

Below, the map of the pass in the sky, calculated by the Heavens-Above site.

Culminating at 85° (remember zenith is at 90°) and a magnitude of -3,8, Lyon will enjoy a very beautiful pass.

To summarise.

An altitude of 10° a few seconds after 9.01 p.m. (to the West-North-West)

At 85° at its highest a few seconds after 9.04 p.m. (more or less at the zenith)

Enters the Earth’s shadow (at 15°) a few seconds after 9.07 p.m. (East-South-East)

 

Marseille Pass

A fine pass for the Phocean city, even if it is lower than Lyon. Look for a clear North horizon. The ISS will pass close to the Great Bear.

Below, the map of the pass in the sky, calculated by the Heavens-Above site.

Our marker, again, will be Venus, looking to the right and a little below it. The ISS will, however, climb to 65°, which will enable you to see it quite high in the sky. A fine maximum magnitude of -3.6.

To summarise.

10° of altitude a few seconds after 9.02 p.m. (to the North-West)

At 65° at its highest at 9.05 p.m. (North-North-East)

Enters the Earth’s shadow (at 18°) a few seconds after 9.07 p.m. (East-South-East)

Who will be aboard the ISS?

At the moment, the station is manned by a crew of three people, Expedition 62. They must return to Earth towards mid-April.

L’équipage de l’Expédition 62. Le Russe Oleg Skripochka (commandant) porte aisément sur ses épaules, grâce à l’impesanteur, l’Américaine Jessica Meir et son compatriote Andrew Morgan. Crédit : NASA

L’équipage de l’Expédition 62. Le Russe Oleg Skripochka (commandant) porte aisément sur ses épaules, grâce à l’impesanteur, l’Américaine Jessica Meir et son compatriote Andrew Morgan.
Crédit : NASA