China and Europe together launch ESASky in Chinese

With the close collaboration between National Astronomical Observatories, Chinese Academy of Sciences (NAOC) and European Space Agency (ESA), ESA’s world-leading interactive celestial atlas, ESASky, has now been translated into Chinese. Alongside its English and Spanish language versions, this makes ESASky available to nearly one quarter of the world population in their native tongue. The ESASky in Chinese is scheduled to be available on June 11, 2020 (UST).

NAOC and ESA have long-time collaboration in science research and scientific data open access. NAOC is the host institute of China’s National Astronomical Data Center (NADC) and ChineseVirtual Observatory (China-VO), an online astronomical research and education environment that provides seamless, global access to astronomical information. The ESASky in Chinese is one of the latest achievements between the two partners.

ESASky is a discovery portal that provides full access to the entire sky. It is a web-based application allowing users to zoom in on any celestial object they may be interested in. Once there, they can look at data collected from more than fifty among space missions and ground-based observatories across all frequencies of the electromagnetic spectrum.

Containing data collected since 1978, ESASky now contains more than half a million images, almost nine and a half million spectra and catalogues that list around three billion sources. With a source inventory that ranges from planets, moons, asteroids and comets in our Solar System to stars, the interstellar medium that pervades our Milky Way galaxy and external galaxies far beyond our own, ESASky is rapidly becoming the go-to interface to visualise and access astronomical data taken by any mission in space or by any large ground-based observatory.

The application is under the responsibility of the ESAC Science Data Centre (ESDC), based at the European Space Astronomy Centre (ESAC), Madrid, Spain.

“We'd been getting feedbacks from users of our astronomy archives that they'd like one easy interface to access all data,” says Deborah Baines, ESA’s Astronomy Archives Science Lead.

“More and more astronomers are working in multiple wavelengths now. So they need data from all regions of the electromagnetic spectrum, but they often don’t have the time to go to the specific archives and reduce the data and so on. They want to be able to find science-ready data,” says Baines.

Traditionally, astronomers have concentrated their research in individual wavebands, for example, specialising in radio astronomy or X-ray astronomy. They would learn how the data was collected with the specific instrumentations of that particular field, and how to process the raw observations into useable ‘science-ready’ data, a process called data reduction. However, the archives team noticed that as more and more mission data became available, this traditional workflow was disappearing.

“An astronomer doesn't always care if the data has been taken by an ESA space mission or a ground-based observatory, they just want to be able to get the data easily, and fast,” says Baines. The easier it is for an astronomer to find the data needed, the easier it is for progress to be made.

So, in 2014, the ESA Archives team put together a prototype of ESASky. With the feedback they received from users, they developed and adapted the app to the point of first release in 2016.

As well as being a hit with professional astronomers, it has also become a resource for amateur astronomers and members of the general public who like to ‘browse’ the wonders of the Universe. They constituted more than a third of all ESASky visitors last year and their numbers continue to grow. To help them, the team invested effort to make the app’s design responsive so it can be used on mobile devices.

Since ESDC is based in Spain, translation into Spanish was an obvious next step, with native Spanish speakers on the team who could handle translations on the fly. The current Chinese translation came about because twice a year the team attends meetings of the InternationalVirtual Observatory Alliance (IVOA).

The IVOA has been meeting twice a year since 2000 and creates standard for astronomical data formats, allowing different observatories and missions to more easily swap data.

“It’s what made ESASky very easy to develop. We can link with other data centres and access their data because we're all using the same standards,” says Baines.

The ESASky team were offering to incorporate data from China’s Large Sky Area Multi Object Spectroscopic Telescope (LAMOST), when their Chinese counterparts offered to translate the app. “The ESASky project brings together data and astronomers from all over the world. It is a valuable asset on many levels, from astronomy to space science, from professional users to education and public outreach, from basic research to Big Data and cloud computing leading information and communications technology,” says Dr. Chenzhou Cui, a research professor at NAOC and Executive Director of NADC.

In the future, the ESASky team will be adding more datasets from ESA, NASA, the Japan Aerospace Exploration Agency (JAXA), and other major astronomical data centres. Thanks to the data protocols set by the IVOA, the app can now access information taken by ground based observatories such as the European Southern Observatory, and can integrate data from NASA’s Mikulski Archive for Space Telescopes (MAST) and the Canadian Astronomy Data Centre (CADC).

“The big aim is to make ESASky a gateway for astronomers to find all data that's been taken,” says Bruno Merín, Head of the ESAC Science Data Centre.

The ESASky in Chinese can be accessed at