Terms of Service
Last updated: 11 August 2026
1. General provisions and Service Provider details
1.1. These Terms and Conditions set out the rules for using the SkyLep website, available at skylep.com, and the rules for the provision of electronic services through it.
1.2. The operator of the website and the service provider is:
Nocne Niebo Zbigniew Zając, address: os. Bolesława Śmiałego 38/45, 60-682 Poznań, Tax ID (NIP): 9720990828, email: zbigniew.zajac@nocneniebo.pl
hereinafter referred to as the “Service Provider”.
1.3. For the purposes of these Terms and Conditions:
a) “SkyLep” or the “Website” means the skylep.com website, together with its subpages, tools, and publicly available modules,
b) “User” means any person using the Website,
c) “Service” means a service provided electronically through SkyLep.
1.4. These Terms and Conditions are made available free of charge on the Website in a manner that enables them to be displayed, saved, and reproduced.
1.5. Use of SkyLep’s basic public functions does not require creating an account.
1.6. As of the date of the last update of these Terms and Conditions, the public services described herein are provided free of charge.
1.7. Detailed rules regarding the processing of personal data, technical data, and information stored on the User’s device are described in the SkyLep Privacy Policy.
2. Types and scope of SkyLep services
2.1. SkyLep is a website dedicated to astronomy, sky observation, objects in Earth orbit, and astronomical phenomena.
2.2. In particular, the following Services may be provided through SkyLep:
a) providing articles, descriptions, information, and other materials related to astronomy and outer space,
b) an interactive sky map showing the positions of astronomical objects for a selected location and time,
c) searching for astronomical objects and satellites,
d) a database of satellites and other objects in orbit,
e) displaying the current or calculated positions of satellites,
f) displaying satellite paths and trajectories,
g) searching for and displaying predicted satellite passes,
h) displaying information on the visibility of the International Space Station and other objects,
i) calculating and displaying satellite transits across the Sun or Moon,
j) maps, visualisations, and calculations concerning solar eclipses and other astronomical phenomena,
k) tools using the observer’s location to perform astronomical calculations,
l) public SkyLep modules intended for embedding on other websites, where this option has been made available by the Service Provider,
m) other calculators, visualisations, maps, and astronomical tools made available on the Website.
2.3. The scope of available functions may change as SkyLep develops.
2.4. Individual tools may use different data sources, mathematical models, and calculation algorithms.
2.5. Some calculations may be performed directly on the User’s device, while others may be performed through SkyLep’s server infrastructure.
3. Technical requirements for using the Website
3.1. The following are required to use SkyLep’s basic functions:
a) a device with internet access,
b) a current or relatively current web browser supporting modern web standards,
c) JavaScript enabled.
3.2. Certain advanced graphics functions may require support for WebGL technology or other hardware-accelerated graphics features by the User’s browser and device.
3.3. Some functions may use browser storage, in particular localStorage, to remember settings, the observer’s location, or data required for the tools to operate.
3.4. Blocking browser storage may result in some settings not being retained between visits or some functions operating to a limited extent.
3.5. Functions using the device’s location require a browser supporting geolocation and the User’s consent to share the location.
3.6. Sharing the device’s location is not required to use the entire Website. In relevant tools, the User may use other available methods of selecting an observation location, such as a place search engine or a map.
3.7. The Service Provider uses technical solutions to ensure the security of data transmission; however, the use of internet services may involve typical online risks, in particular attempts to exploit software vulnerabilities, malware, or actions by third parties.
3.8. The User should use up-to-date software and apply appropriate security measures to their device.
4. Rules for using the Website
4.1. The User is required to use the Website in accordance with the law, these Terms and Conditions, and the intended purpose of individual functions.
4.2. It is prohibited to undertake actions that may disrupt the proper functioning of SkyLep or hinder its use by other Users.
4.3. In particular, it is prohibited to:
a) attempt to gain unauthorised access to the infrastructure, administrative panels, databases, or other protected elements of the Website,
b) circumvent security mechanisms, query limits, or other technical safeguards,
c) intentionally generate traffic that may overload the Website, its API, or its infrastructure,
d) use automated tools to download data on a mass scale in a manner causing excessive load on the infrastructure,
e) introduce malicious code into the system or undertake actions intended to damage, disrupt, or take control of the Website’s operation,
f) use the Website in a manner contrary to applicable law.
4.4. If, as part of a particular function, the User may submit any data or content to the system, it is prohibited to provide unlawful content.
4.5. Ordinary use of publicly available SkyLep pages, linking to them, and indexing public pages by internet search engines shall not be treated as a breach of these Terms and Conditions, provided that this takes place in accordance with the law and the technical rules made available by the Website.
4.6. If SkyLep provides official code or a mechanism enabling a selected module to be embedded on another website, such a module may be used in accordance with its intended purpose and the technical conditions specified by SkyLep.
4.7. It is prohibited to remove or circumvent the technical safeguards of official embedded modules, impersonate SkyLep, or present a module in a manner that may mislead users as to its origin.
5. Location and location-dependent functions
5.1. Some SkyLep functions use the observer’s location to perform calculations appropriate for a specific place on Earth.
5.2. Location may be used, among other things, to:
a) display the appearance of the sky,
b) determine the positions of objects above the horizon,
c) calculate rises, sets, and visibility of objects,
d) search for satellite passes,
e) calculate transits,
f) display the course of eclipses and other astronomical phenomena.
5.3. Depending on the available function, the User may select a location by:
a) searching for a city or place,
b) indicating a point on a map,
c) manually specifying a location, if the relevant function allows it,
d) using the location made available by the device.
5.4. SkyLep does not access the device’s location without action by the User and consent granted through the browser or operating system.
5.5. The User may refuse access to the device’s location. This may limit the operation of functions requiring knowledge of the observation location but does not prevent use of the remaining parts of the Website.
5.6. The User should verify the accuracy of the selected location before using calculation results, especially in the case of phenomena strongly dependent on the observer’s position.
5.7. Detailed information concerning the processing and storage of location data can be found in the SkyLep Privacy Policy.
6. Astronomical data, calculations, and accuracy limitations
6.1. SkyLep makes every effort to ensure that the information, data, and calculation results provided are as accurate, up-to-date, and consistent with the adopted calculation models as possible.
6.2. Data displayed by SkyLep may originate both from the Website’s own calculations and from external catalogues, databases, and other sources.
6.3. Astronomical and orbital data may be updated periodically. A result obtained at different times may change as a result of newer source data becoming available, a change in the calculation model, or the correction of an error.
6.4. Results concerning the future positions of satellites constitute mathematical forecasts. Their accuracy depends, among other things, on the quality and timeliness of orbital data and the time elapsed since they were determined.
6.5. Results concerning the visibility of phenomena also depend on conditions that SkyLep may not take into account or be able to predict, in particular:
a) cloud cover and other weather conditions,
b) local terrain obstacles and buildings,
c) the actual altitude of the local horizon,
d) observing conditions and light pollution,
e) device parameters and the accuracy of the User’s location,
f) atmospheric phenomena, including refraction.
6.6. Times, positions, directions, altitudes, trajectories, and other parameters provided by SkyLep should be treated as data intended primarily for informational and educational purposes and for planning amateur astronomical observations.
6.7. SkyLep is not a navigation system or a system intended for safety-critical applications.
6.8. Information originating from SkyLep must not be used as the sole source of data for:
a) air, marine, or land navigation,
b) ensuring the safety of persons or property,
c) conducting operations requiring certified or official data,
d) undertaking activities in which inaccuracies in astronomical or orbital data could cause a hazard.
6.9. When observing the Sun or phenomena related to the Sun, the User should use appropriate eye-protection methods and equipment intended for safe solar observation. Information presented by SkyLep does not replace safe observation practices.
6.10. The User is solely responsible for selecting a safe and legally accessible observation location and for observing appropriate safety measures while conducting observations.
7. Copyright and databases
7.1. Elements of SkyLep, in particular software, the Website layout, original texts, graphics, visualisations, interfaces, multimedia materials, and other works created for the Website, may be protected under provisions concerning copyright, databases, or other intellectual property rights.
7.2. Rights to individual elements belong to the Service Provider or the relevant third parties.
7.3. SkyLep may use data, maps, catalogues, software, or other materials originating from external sources. Rights to such materials and the rules for their further use may arise from licences or provisions applicable to the relevant source.
7.4. These Terms and Conditions do not limit the User’s rights arising from fair-use provisions or licences concerning materials originating from third parties.
7.5. It is permitted to place ordinary links leading to publicly available SkyLep pages.
7.6. Without the consent of the relevant rights holder, it is prohibited to copy and distribute protected elements of SkyLep beyond the scope of permitted use or the terms of the relevant licence.
7.7. It is prohibited to systematically download, copy, or re-use a substantial part of SkyLep’s own database in a manner infringing the rights vested in its producer.
7.8. If a particular dataset used by SkyLep is made available by an external provider under a separate licence, these Terms and Conditions do not limit the rights granted directly by that licence.
8. Formation and termination of the service agreement
8.1. Use of SkyLep does not require entering into a written agreement or creating an account, unless separate terms are specified in the future for a specific additional service.
8.2. An agreement for the provision of a specific free Service is concluded when the User begins using it, in particular by opening the relevant page, launching a tool, or sending a request to perform a particular function.
8.3. The agreement is concluded for the duration of use of the relevant Service.
8.4. The User may cease using the Service at any time by closing the page, leaving the Website, ceasing use of the tool, or no longer sending requests to the relevant function.
8.5. The User is not obliged to continue using the Website or retain locally saved settings.
8.6. Data stored locally on the User’s device may be deleted using the relevant Website functions, if available, or by deleting website data in the browser settings.
8.7. The Service Provider may temporarily restrict or disable particular functions due to technical work, failures, security issues, changes in data sources, or the need to carry out updates.
8.8. The Service Provider may cease making a particular free SkyLep function available, in particular in connection with the development of the Website, a change in technology, the discontinuation of a data source, or disproportionate costs of maintaining the function.
8.9. The provisions of this section do not prejudice the User’s rights arising from mandatory provisions of law.
9. Complaints
9.1. The User may submit a complaint concerning the provision of Services or the operation of SkyLep.
9.2. Complaints may be sent by email to:
9.3. To enable efficient handling of a complaint, it is recommended to provide:
a) the name of the function to which the problem relates,
b) the most precise description of the problem possible,
c) the date or approximate time when it occurred,
d) the address of the page on which the problem occurred,
e) technical information that may help reproduce the problem, if known to the User,
f) the expected method of resolving the matter.
9.4. Providing the information specified in section 9.3 is not a condition for considering a complaint if the information submitted makes it possible to determine what the report concerns.
9.5. Consumer complaints shall be considered within 14 days of receipt.
9.6. A response to the complaint shall be sent to the contact address used by the User or indicated in the report.
9.7. Complaints concerning incorrect data or calculation results may require the provision of the location, date, time, object name, or other parameters necessary to reproduce the result.
9.8. A complaint does not exclude or limit rights granted to the consumer under applicable provisions.
10. Liability and availability of the Website
10.1. The Service Provider exercises due care to ensure the proper and secure operation of SkyLep.
10.2. Due to the nature of internet services, it is not possible to guarantee uninterrupted availability of all Website functions.
10.3. Temporary interruptions may occur, in particular due to:
a) maintenance work or updates,
b) hardware or software failures,
c) telecommunications infrastructure failures,
d) issues on the part of external data or service providers,
e) actions intended to ensure the security of the Website,
f) events beyond the reasonable control of the Service Provider.
10.4. Where possible, planned work that may cause significant restrictions in availability shall be carried out in a manner limiting inconvenience to Users.
10.5. The Service Provider may correct errors in data, algorithms, and software and change the operation of tools in order to improve their quality, accuracy, performance, or security.
10.6. The Service Provider does not guarantee that a result obtained using an earlier version of an algorithm will be identical to a result obtained after a data or calculation-model update.
10.7. The Service Provider shall not be liable for decisions made by the User using SkyLep data in applications inconsistent with the purpose specified in these Terms and Conditions, subject to mandatory provisions of law.
10.8. The Service Provider shall not be liable for incorrect results directly resulting from the User providing an incorrect location, date, time, or other input parameters, provided that SkyLep correctly processed the data provided.
10.9. No provision of these Terms and Conditions excludes or limits the Service Provider’s liability to the extent that such exclusion or limitation would be impermissible under applicable provisions, in particular provisions protecting consumers.
11. Amendments to the Terms and Conditions and final provisions
11.1. These Terms and Conditions shall apply from the date of their publication on the Website.
11.2. The Service Provider may amend these Terms and Conditions, in particular in the event of:
a) changes in legal provisions affecting the operation of SkyLep,
b) the introduction of new Services,
c) a significant change in the operation of existing Services,
d) the introduction of user accounts, paid functions, subscriptions, or other new service-provision models,
e) changes to the Service Provider’s details,
f) the need to clarify security rules or rules for using the infrastructure,
g) the need to adapt these Terms and Conditions to technological changes.
11.3. The current version of these Terms and Conditions shall be published on the Website together with the date of the last update.
11.4. Amendments to these Terms and Conditions do not prejudice rights acquired by Users before the amendments enter into force.
11.5. In the case of services provided on a one-off basis or during a single session, the version of the Terms and Conditions in force at the time of using the relevant Service shall apply.
11.6. If SkyLep introduces in the future a continuous service, a user account, a paid service, or another model resulting in a continuing contractual relationship, the method of notifying Users of amendments to the Terms and Conditions may be specified separately, as appropriate to the nature of that Service.
11.7. In matters not governed by these Terms and Conditions, Polish law shall apply, taking into account consumer-protection provisions and other mandatory provisions applicable to the User.
11.8. Any disputes shall be resolved by the competent court in accordance with applicable legal provisions.
11.9. In matters concerning these Terms and Conditions or the operation of SkyLep, the Service Provider may be contacted at: